溶液中蛋白质构象微弱变化的二维相关红外光谱研究
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摘要
研究蛋白质去折叠路径及其在外扰下的构象变化,对揭示其折叠途径和机理至关重要。其中,如何区分蛋白质的折叠/去折叠途径是完全的协同过程、还是包含早期事件的非协同过程一直是蛋白质科学研究中重要的科学难题。红外吸收光谱是分析溶液中蛋白质二级结构含量及其变化的有力手段,而二维相关红外分析不但对相互重叠的蛋白质振动峰具有很强的分辨力,而且对于微弱的结构变化也具有独特的敏感性,它的提出更为利用红外吸收光谱揭示溶液中蛋白质的构象变化提供了广阔的前景。本论文中,我们分别选择热去折叠机制尚存争议的模型蛋白——核糖核酸酶A(RNase A)和压力去折叠机制仍有争议的多功能蛋白——泛素(ubiquitin)为研究对象,对其在温度、压力诱导下的预相变过程存在与否以及相应过程中的二级结构变化及顺序等进行了详尽的研究。主要研究内容及结论如下:(1)首次利用样本-样本二维相关分析和化学计量学中的主成分分析法(PCA)观测到变温过程中位于45 oC的RNase A的预相变过程,该信息由传统的单频红外谱峰分析无法揭示;同时还利用波数-波数二维相关分析对预相变过程所包含的构象微弱变化进行了详细分析,揭示出热诱导RNase A的预相变过程主要涉及α2和β1的结构变化。这些结果显示了二维相关光谱与PCA相结合方法在揭示预相变过程中二级结构微弱变化方面的独特优势。(2)我们还对比研究了还原剂存在条件下RNase A的热诱导去折叠过程,结果表明该过程也存在早期事件;还原剂的参与使得预相变过程发生的温度提前,同步相关光谱切谱的定量比较表明早期事件所包含的结构变化相对于主相变过程极其微弱。(3)本研究还利用二维相关红外光谱和主成分分析相结合揭示了压力扰动下ubiquitin去折叠过程中早期的微弱二级结构变化,结果表明压力诱导下的早期事件及相转变行为与压力诱导的水分子的结构变化及蛋白质水合密切相关。
Over the past decades, much effort has been devoted to investigating the mechanism of protein folding and the main interactions that govern this process. Exploring the folding problem and the structure-function relationship will enable the modification and design of novel proteins or peptide mimetics, which can play crucial roles in bio- and nanotechnology. The protein structural transitions that occur in the pathway are at the heart of the specific conformational changes that form the individual intermediates involved in the rate-limited pathways that can distinguish one pathway from another.
     The analysis of protein unfolding pathways and the identification of specific conformational changes under perturbation are of fundamental importance for protein folding. Much effort has been devoted in recent years to elucidate whether the protein’s folding/unfolding is a fully cooperative process or whether it contains sequential events. To address such question, one needs the combined use of variable analytical tools. In this study, sample-sample two dimensional correlation spectroscopy (SS 2D), principal component analysis (PCA) in combination with variable-variable two-dimensional correlation spectroscopy (VV 2D) have provided answers to this question.
     Principal component analysis (PCA) is a well-established technique in statistics and chemometrics that gives a precise mathematical estimation of changes along the sample and variable vectors. This method is a well-known pattern recognition and multivariate data display method. Not only can it compare any object clusters, but it can also display any relationships among variables as well as among variables and objects. In sample-sample (SS) 2D correlation, the relationship between different samples observed under various states of perturbation is studied by examining the similarity or difference of their spectral trace patterns along the spectral variable. By use of SS 2D correlation methodology, one can follow the variable profiles directly. In variable-variable (VV) 2D correlation spectroscopy, it enables one to establish the correlation between different secondary structures of the protein through selective correlation peaks for a given perturbation. This provides detailed information on the process under investigation, including the sequence of events and the possibility of band assignments. Fourier transform infrared spectroscopy (FTIR) is a useful technique to investigate the secondary structure of proteins. 2D IR correlation spectroscopy is very powerful to unravel the highly complicated infrared bands of proteins since the conventional IR fail to tell the difference immediately for the minor structural variations.
     On the basis of the above, our studies will be focused on the following fields.
     1. Thermal kinetics study of ribonuclease A (RNase A) in solution by two-dimensional correlation infrared spectroscopy
     Thermal unfolding of RNase A in Tris-DCl buffer solution is studied by Fourier transform infrared (FT-IR) spectroscopy. SS 2D correlation spectroscopy in combination with PCA are applied to these spectral data to reveal the thermal kinetics of RNase A. Using SS 2D spectroscopy subtle pretransition could be detected at 45 oC in addition to the main unfolding transition at 66 oC, which indicates that the thermal unfolding of RNase A does not proceed via a two-state mechanism, involving an intermediate. The second scores plot of PCA constructed from temperature-dependent IR spectra also certified a minor pretransition at 46 oC as well as a clear main transition at 66 oC. But the loadings plots of PCA suggest only the general structural variations because the second loadings plot has coupled the contribution both of pretransition and main transition conformational changes. Advantages of 2D correlation over PCA, including the identification of secondary structure and sequential order of conformational changes, were also discussed.
     Specific temperature regions identified by SS 2D were selected to construct VV 2D to monitor the conformational changes of RNase A during the observed transitions in detail. In the pretransition process, the observed structural variations are associated with local conformational changes ofα2 and the modification ofβ1; in the main unfolding, changes in irregular andα-helical structures are followed by those in theβ-sheet structure including the antiparallelβ-sheet components, resulting in the loss of secondary structure. Moreover, the gain ofβ-turn and a small amount of anti-parallelβ-strands reveal that the pretransition may involve changes in hydration and protein aggregations.
     Therefore, the present study demonstrates the great potential of SS 2D in revealing subtle phase transition of proteins in aqueous solutions. This pretransition cannot be detected by a single-frequency analysis of the original infrared spectra of RNase A. However, VV 2D correlation spectra reveal the variations in the structure of RNase A and their orders of variations that occur during these transitions.
     2. Thermally induced early events of RNase A under reducing conditions: Evidenced by principal component analysis and two-dimensional correlation infrared spectroscopy
     In this chapter, thermally induced early unfolding events of ribonuclease A (RNase A) in the presence of 2-mercaptoethanol are evidenced successfully by PCA and two-dimensional correlation infrared (2D IR) spectroscopy. The analyses of secondary structural changes in different stages have clearly distinguished the early events from the main unfolding in the temperature course of RNase A.
     With fluorescence and infrared spectroscopy, we have demonstrated that the mechanism of the thermally induced reductive unfolding pathway and the related structural variations. Especially, the combined use of PCA and 2D IR correlation spectroscopy clarified that the early events of RNase A under reducing conditions are in a non-cooperative process, which in contrast to the unfolding under non-reducing conditions where a pretransitional temperature was revealed at 46 oC. 2D IR correlation analysis also revealed that in the early stage of the reductant thermal unfolding the subtle structural variations of the orderedβ-sheet in RNase A dominated; identical conformational changes occured at lower temperature for reductive RNase A as those under non-reducing conditions. It is reasonable that in stage I the change ofβ1 andα2 might be the main process. In stage II,β1 was further unfolded, changes ofα1 and another species ofβ2 andβ4 involved, that was, theβ-sheet was further unfolded as temperature increased.
     In general, the addition of the reductant to the solution of RNase A apparently induced a lower transition temperature of the pretransition. The quantitative analysis of the power spectra reveals that the early structural changes for reductive RNase A were definitely minor ones in relative to those in main unfolding. This study also revealed the usefulness of generalized 2D correlation spectroscopy and the quantitative utilization of its power spectrum to explore minor non-cooperative early events and the closely related subtle structural changes.
     3. High-pressure induced pretransition of ubiquitin
     Pressure as an experimental variable provides unique information about the microscopic properties of the materials being studied, which is different from the traditional external perturbation variable (such as temperature). It is known that the measurements of temperature and/or pressure-induced process are extremely useful strategies. The non-covalent inter-molecular interaction of biological molecules is easy to be changed by pressure. Therefore, the coupling of high pressure, as an external perturbation, with 2D-IR and applying it to protein research has proven to be an insightful method for the investigation of proteins, although few concerning papers have been published so far. However, the requirement of a more sophisticated diamond anvil cell (DAC) for IR measurements makes it somewhat difficulty to employ pressure as a routine source of spectral intensity changes.
     In this chapter, the methodology will be applied to more meaningful and complicated protein, ubiquitin. By using SS 2D correlation spectroscopy and PCA,in addition to the main unfolding transition at around 689.9 MPa, subtle structural 7 transition could be detected at 392.2 MPa. This indicates that the pressure-induced unfolding of ubiquitin does not proceed via a two-state mechanism. Specific pressure regions identified by PCA were selected to construct VV 2D in order to monitor the conformational changes of ubiquitin during the observed transitions in detail. In the low pressure region, the structural variations are associated withα-helix, side chain and minor aggregation; in the main transition, disordered structure,α-helix and side chain proceeded beforeβ-sheet. The quantitative comparison of power spectra demonstrate that the intensity variations from early pressure region accounts for around 2.5 % that of the main pressure unfolding. Meanwhile, with the pressure increasing, the integration area of water peak and amide I has similar trends and it demonstrated that the early structural variations was associated with the water behavior and protein hydration. The present results suggest that the pressure-induced unfolding of ubiquitin was not a complete two state process or only because of water behavior. Further exploration of the pressure stability of ubiquitin is currently being investigated in our laboratory.
引文
[1]阎隆飞,孙之荣.蛋白质分子结构[M].北京:清华大学出版社, 1999.
    [2]王镜岩,朱圣庚,徐长法.生物化学[M].北京:高等教育出版社, 2002.
    [3] NELSON D L, COX M M. Lehninger principles of biochemistry [M]. 4th ed. NY, USA: W. H. Freeman and Company, 2004.
    [4] LEVINTHAL C. Are there pathways for protein folding? [J]. J. Chem. Phys., 1968, 65:44-45.
    [5] WETLAUFER D B. Nucleation, rapid folding, and globular intrachain regions in proteins [J]. Proc. Natl. Acad. Sci. USA, 1973, 70(3):697-701.
    [6]BALDWIN R L. The search for folding intermediates and the mechanism of protein folding [J]. Annu. Rev. Biophys., 2008, 37:1-21.
    [7] SANTUCCI R, SINIBALDI F, FIORUCCI L. Protein folding, unfolding and misfolding: role played by intermediate States [J]. Mini Rev. Med. Chem., 2008 8(1):57-62.
    [8] UDGAONKAR J B. Multiple routes and structural heterogeneity in protein folding [J]. Annu. Rev. Biophys., 2008, 37: 489-510.
    [9] BAI Y, SOSNICK T R, MAYNE L, et al. Protein folding intermediates: Native-state hydrogen exchange [J]. Science, 1995, 269:192-197.
    [10] THIBODEAU P H, BRAUTIGAM C A, MACHIUS M, et al. Side chain and backbone contributions of Phe508 to CFTR folding [J]. Nat. Struct. Mol. Biol., 2005, 12: 10-16.
    [11] FENG H, VU N D, BAI Y. Detection of a hidden folding intermediate of the third domain of PDZ [J]. J. Mol. Biol., 2005, 346(1): 345-353.
    [12] ZHOU Z, FENG H, BAI Y. Detection of a hidden folding intermediate in the focal adhesion target domain: Implications for its function and folding [J]. Proteins, 2006, 65(2): 259-265.
    [13] FERSHT A R. Transition-state structure as a unifying basis in protein-folding mechanisms: contact order, chain topology, stability, and the extended nucleus mechanism [J]. Proc. Natl. Acad. Sci. USA, 2000, 97(4): 1525-1529.
    [14] KATO H, FENG H, BAI Y. The folding pathway of T4 lysozyme: the high-resolution structure and folding of a hidden intermediate [J]. J. Mol. Biol., 2007, 365(3): 870-880.
    [15] RELIGA T L, MARKSON J S, MAYOR U, et al. Solution structure of a protein denatured state and folding intermediate [J]. Nature, 2005, 437(7061):1053-1056.
    [16] PTITSYN O B. Molten globule and protein folding [J]. Adv. Prot. Chem., 1995, 47, 83-229.
    [17] CHEN Y, DING F, NIE H, et al. Protein folding:then and now [J]. Arch. Biochem. Biophys., 2008, 469: 4-19.
    [18] SHAKHNOVICH E I, FINKELSTEIN A V. Theory of cooperative transitions in protein molecules. I. Why denaturation of globular protein is a first-order phase transition [J]. Biopolymers, 1989, 28(10): 1667-1680.
    [19] GOTO Y and FINK A L. Phase diagram for acidic conformational states of apomyoglobin [J]. J. Mol. Biol., 1990, 214(4): 803-805.
    [20] DOLGIKH D A, ABATUROV L V, BOLOTINA I A, et al. Compact state of a protein molecule with pronounced small-scale mobility: bovine alpha-lactalbumin [J]. Eur Biophys J., 1985, 13(2):109-121.
    [21] PTITSYN O B, PAIN R H, SEMISOTNOV G V, et al. Evidence for a molten globule state as a general intermediate in protein folding [J]. FEBS Letters, 1990, 262(1): 20-24.
    [22] JANIAK M J, SMALL D M, SHIPLEY G G. Nature of the thermal pretransition of synthetic phospholipids: dimyristoyl- and dipalmitoyllecithin [J]. Biochemistry, 1976, 15(21): 4575-4580.
    [23] GIANAZZA E, EBERINI I, SANTI O, et al. Denaturant-gradient gel electrophophoresis: technical aspects and practical applications [J]. Analytica Chimica Acta., 1998, 372: 99-120.
    [24]童宇峰,郁鉴源.仪器分析方法研究蛋白质体外折叠的进展[J].分析测试学报,1997, 16: 76-81.
    [25] JONAS J. High-resolution nuclear magnetic resonance studies of proteins [J]. Biochim Biophys Acta., 2002, 1595(1-2):145-159.
    [26] OZAWA K, WU P S, DIXON N E, et al. N-Labelled proteins by cell-free protein synthesis. Strategies for high-throughput NMR studies of proteins and protein-ligand complexes [J]. FEBS J., 2006, 273(18):4154-4159.
    [27] NORMA J. GREENFIELD N J. Methods to estimate the conformation of proteins and polypeptides from circular dichroism data [J]. Anal. Biochem., 1996, 235: 1-10.
    [28] SREERAMA N, VENYAMINOV S Y, WOODY R W. Estimation of protein secondary structure from circular dichroism spectra: inclusion of denatured proteins with native proteins in the analysis [J]. Anal. Biochem., 2000, 287: 243-251.
    [29] KELLY S M, JESS T J, PRICE N C. How to study proteins by circular dichroism [J]. Biochim. Biophys. Acta, 2005, 1751: 119-139.
    [30] SULTAN N A, RAO R N, NADIMPALLI S K, et al. Tryptophan environment, secondary structure and thermal unfolding of the galactose-specific seed lectin from Dolichos lablab: Fluorescence and circular dichroism spectroscopic studies [J]. Biochim. Biophys. Acta, 2006, 1760: 1001-1008.
    [31] MURALI J, JAYAKUMAR R. Spectroscopic studies on native and protofibrillar insulin [J]. J. Struct. Biol., 2005, 150: 180-189.
    [32] VAN DAEL H, CHEDAD A, VANHOOREN A, et al. Influence of experimental conditions and Trp mutations on the stability and the folding characteristics of goat a-lactalbumin [J]. J. Mol. Struct., 2005, 744-747: 155-160.
    [33] BUSHMARINA N A, KUZNETSOVA I M, BIKTASHEV A G, et al. Partially folded conformations in the folding pathway of bovine carbonic anhydrase II: a fluorescence spectroscopic analysis [J]. Chem. Biochem., 2001, 2: 813-821.
    [34] KUDELSKI A. Analytical applications of Raman spectroscopy [J]. Talanta, 2008, 76(1):1-8.
    [35] BAENA J R, LENDL B. Raman spectroscopy in chemical bioanalysis [J]. Curr. Opin. Chem. Biol., 2004, 8(5):534-539.
    [36]林应章,周筠梅.振动光谱与蛋白质二级结构[J].生物物理学报,1989,5(4): 428-439.
    [37] FRUSHOUR B G, KOENING J L. Raman spectroscopy of proteins [M] // Clark RJH, Hester RE. Advances in Infrared and Raman Spectroscopy. New York: John Wiley and Sons, 1975, 2: 35-97.
    [38] KOENIG J L, TABB D L. Infrared spectra of globular proteins in aqueous solution, analytical applications of FTIR to molecular and biological systems [M]. Netherlands: D.Reidel publishing company, 1980, 241-255.
    [39] SUSI H, BYLER D M. Protein structure by fourier transform infrared spectroscopy: second derivative spectra [J]. Biochem. Biophys. Res. Commun., 1983, 115: 391-397.
    [40] BYLER D M, SUSI H. Examination of the secondary structure of proteins by deconvolved FTIR spectra [J]. Biopolymers 1986, 25(3): 469-487.
    [41] BARTH A, ZSCHERP C. What vibrations tell us about proteins [J]. Q. Rev. Biophys., 2002, 35: 369-430.
    [42] FABIAN H, M?NTELE W. Infrared spectroscopy of proteins [M]// Chalmers J M, Griffiths P R, Handbook of Vibrational Spectroscopy, Chichester: John Wiley and Sons, 2002, 5:3399-3426.
    [43] GOORMAGHTIGH E, CABIAUX V, RUYSSCHAERT J M. Determination of soluble and membrane protein structure by Fourier transform infrared spectroscopy. III. Secondary structures [J]. Subcell. Biochem., 1994, 23: 405-450.
    [44] CHIRGADZE Y N, NEVSKAYA N A. Infrared spectra and resonance interaction of amide-I vibration of the parallel-chain pleated sheet [J]. Biopolymers, 1976, 15: 627-636.
    [45] TORII H, TASUMI M. Model calculations on the amide-I infrared bands of globular proteins [J]. J. Chem. Phys., 1992, 96: 3379-3387.
    [46] SUSI H, BYLER D M. FTIR study of proteins with parallelβchains [J]. Arch. Biochem. Biophys., 1987, 258: 465-469.
    [47] KHURANA R, FINK A L. Do parallelβ-helix proteins have a unique Fourier transform infrared spectrum [J]? Biophys. J., 2000, 78: 994-1000.
    [48] DONG A, HUANG P, CAUGHEY W S. Protein secondary structures in water from second-derivative amide I infrared spectra [J]. Biochemistry, 1990, 29(13): 3303-3308.
    [49]沈怡,彭云,武培怡等.二维相关振动光谱技术[J].化学进展, 2005, 17 (3): 499-513.
    [50]余婧,武培怡.二维相关荧光光谱技术[J].化学进展, 2006, 18 (12): 1691-1702.
    [51] BAX A. Two Dimensional Nuclear Magnetic Resonance in Liquids [M]. Dordrecht: Reidel Publishing Company, Delft University Press, 1982.
    [52] ERNST R R, BODENHAUSEN G, WAKAUN A. Principles of Nuclear Magnetic Resonance in One and Two Dimensions [M]. Oxford: Oxford University Press, 1987.
    [53] NODA I, DOWREY A E, MARCOTT C, et al. Generalized two-dimensional correlation spectroscopy [J]. Appl. Spectrosc., 2000, 54: 236A-248A.
    [54] NODA I. Two-Dimensional Infrared (2D IR) spectroscopy: theory and applications [J]. Appl . Spectrosc., 1990, 44: 550-561.
    [55] NODA I. Generalized two-dimensional correlation method applicable to infrared, raman and other types of spectroscopy [J]. Appl. Spectrosc., 1993, 47: 1329-1336.
    [56] GREGORIOU V G, CHAO J L, TORIUMI H , et al, Time-resolved vibrational spectroscopy of an electric field-induced transition in a nematic liquid crystal by use of step-scan 2D FT-IR [J]. Chem. Phys. Lett., 1991, 179: 491-496.
    [57] ATAKA K, OSAWA M. In situ infrared study of water-sulfate coadsorption on gold (111) in sulfuric acid solutions [J]. Langmuir, 1998 , 14 : 951-959.
    [58] OZAKI Y, LIU Y L, NODA I. Two-dimensional infrared and near-infrared correlation spectroscopy: applications to studies of temperature-dependent spectral variations of self-associated molecules [J]. Appl . Spectrosc., 1997 , 51(4) : 526-535.
    [59] CZARNECKI M A , MAEDA H , OZAKI Y, et al . Resolution enhancement and band assignments for the first overtone of OH stretching mode of butanols by two-dimensional near-infrared correlation spectroscopy. Part I: sec-Butanol [J]. Appl. Spectrosc., 1998, 52(7): 994-1000.
    [60] JIANG H J, WU P Y, YANG Y L. Variable temperature ftir study of poly (ethylene-co-vinyl alcohol)-graft-poly(ε-caprolactone) [J]. Biomacromolecules, 2003, 4: 1343-1347.
    [61] WANG Y, MURAYAMA K, MYOJO Y, et al. Two-dimensional fourier transform near-infrared spectroscopy study of heat denaturation of ovalbumin in aqueous solutions [J]. J. Phys. Chem. B, 1998, 102: 6655-6662.
    [62] NAKANO T, SHIMADA S , SAITOH R, et al. Transient 2d ir correlation spectroscopy of the photopolymerization of acrylic and epoxy monomers [J]. Appl. Spectrosc., 1993, 47(9): 1337-1342.
    [63] NODA I. Two-dimensional infrared spectroscopy [J]. J. Am. Chem. Soc., 1989, 111: 8116-8118.
    [64] NODA I, MARCOTT C. Two-dimensional Raman (2D Raman) correlation spectroscopy study of non-oxidative photodegradation ofβ-carotene [J]. J. Phys. Chem. A , 2002, 106: 3371 -3376.
    [65]徐金泽,赵雨,赵冰等.二维拉曼相关光谱研究稀土离子Eu3+对血红蛋白结构的影响[J].高等学校化学学报, 2002, 23(6) : 1110 -1112.
    [66] SHEN Y, CHEN F E , WU P Y, et al. A two-dimensional Raman spectroscopic study on the structural changes of a polythiophene film during the cooling process [J]. J. Chem. Phys., 2003, 119(21): 11415-11419.
    [67] GENG L, COX J M, HE Y. Dynamic two-dimensional fluorescence correlation spectroscopy. Generalized correlation and experimental factors [J]. Analyst, 2001, 126: 1229-1239.
    [68] CHOI H C, JUNG YM, NODA I, et al. A study of the mechanism of the electrochemical reaction of lithium with coo by two-dimensional soft X-ray absorption spectroscopy (2d XAS), 2d Raman, and 2d heterospectral XAS-Raman correlation analysis [J]. J. Phys. Chem. B, 2003, 107: 5806-5811.
    [69] IZAWA K, OGASAWARA T , MASUDA H, et al.Two-dimensional correlation gel permeation chromatography (2D GPC) study of 1h,1h,2h,2h-perfluorooctyltriethoxysilane sol-gel polymerization process [J]. J . Phys. Chem. B, 2002, 106: 2867-2874.
    [70] IZAWA K, OGASAWARA T, MASUDA H, et al. Two-dimensional correlation gel permeation chromatography study of octyltriethoxysilane sol-gel polymerization process [J]. Macromolecules, 2002, 35(1): 92-96.
    [71] SA?IC S, MUSZYNSKI A, OZAKI Y. A new possibility of the generalized two-dimensional correlation spectroscopy. 2. Sample-sample and wavenumber-wavenumber correlations of temperature-dependent near-infrared spectra of oleic acid in the pure liquid state [J]. J. Phys. Chem. A, 2000, 104(27): 6388-6394.
    [72] IWAHASHI M, YAMAGUCHI Y, KATO T, et al. Temperature dependence of molecular conformation and liquid structure of cis-9-octadecenoic acid [J]. J. Phys. Chem., 1991, 95(1): 445-451.
    [73] IWAHASHI M, HACHIYA N, HAYASHI Y, et al. Dissociation of dimeric cis-9-octadecenoic acid in its pure liquid state as observed by near-infrared spectroscopic measurement [J]. J. Phys. Chem., 1993, 97(13): 3129-3133.
    [74] WU Y, YUAN B, ZHAO J G et al. Hybrid two-dimensional correlation and parallel factor studies on the switching dynamics of a surface-stabilized ferroelectric liquid crystal [J]. J. Phys. Chem. B., 2003, 107, 7706-7715.
    [75] WU Y, JIANG J H, OZAKI Y. A new possibility of generalized two-dimensional correlation spectroscopy: hybrid two-dimensional correlation spectroscopy [J]. J. Phys. Chem. A., 2002, 106(11): 2422-2429.
    [76] WU Y, MEERSMAN F, OZAKI Y. A novel application of hybrid two-dimensional correlation infrared spectroscopy: exploration of the reversibility of the pressure- and temperature-induced phase separation of poly (N-isopropylacrylamide) and poly (N-isopropylmethacrylamide) in aqueous solution [J]. Macromolecules, 2006, 39(3):1182-1188.
    [77] NODA I. Recent advancement in the field of two-dimensional correlation spectroscopy [J]. J. Mol. Struc., 2008, 883-884: 2-26.
    [78] ERNST R R, BODENHAUSEN G, WOKAUN A. Principles of Nuclear Magnetic Resonances in One and Two Dimensions [M]. London/New York: Oxford University Press, 1987.
    [79] NODA I. Progress in two-dimensional (2D) correlation spectroscopy [J]. J Mol Struct., 2006, 799(1-3): 2-15.
    [80] LI Y, SUN S, ZHOU Q, et al. Identification of American ginseng from different regions using FT-IR and two-dimensional correlation IR spectroscopy [J]. Vib. Spectrosc., 2004, 36(2): 227-232.
    [81] WANG Y, GAO W, NODA I, et al. A modified mean normalization method to reduce the effect of peak overlap in two-dimensional correlation spectroscopy [J]. J Mol. Struct., 2006, 799(1-3):128-133.
    [82]吴瑾光.近代傅立叶变换红外光谱技术及应用(上) [M].北京:科学技术出版社,1994.
    [83] MALINOWSKI E R. Factor Analysis in Chemistry [M]. New York: John Wiley and Sons, 2002.
    [84] MORGAN E. Chemometrics, Experimental Design [M]. Chichester: John Wiley and Sons, 1987.
    [85]许禄,邵学广.化学计量学方法[M].北京:科学出版社, 1995.
    [86]何晓群.多元统计分析[M].北京:中国人民大学出版社, 2008.
    [87] CZARNIK-MATUSEWICZ B, PILORZ S, ASHTON L, et al. Potential pitfalls concerning visualization of the 2D results [J]. J. Mol. Struct., 2006, 799(1-3):253-258.
    [88] WU Y, MURAYAMA K, OZAKI Y, two-dimensional infrared spectroscopy and principle component analysis studies of the secondary structure and kinetics of hydrogen-deuterium exchange of human serum albumin [J]. J. Phys. Chem. B 2001, 105(26):6251-6259.
    [89] JUNG Y M, YANG I S. Details of phonon modes of YNi2B2C studied by principal component analysis and two-dimensional correlation analysis [J]. Vib. Spectrosc., 2006, 42(1):161-164.
    [90] WATANABE A, MORITA S, KOKOT S, et al. Drying process of microcrystalline cellulose studied by attenuated total reflection IR spectroscopy with two-dimensional correlation spectroscopy and principal component analysis [J]. J. Mol. Struct., 2006, 799 (1-3):102-110.
    [91] A. WATANABE, S. MORITA, Y. OZAKI. A study on water adsorption onto microcrystalline cellulose by near-infrared spectroscopy with two-dimensional correlation spectroscopy and principal component analysis [J]. Appl. Spectrosc. 2006, 60(9):1054-1061.
    [92] JUNG Y M, SHIN H S, KIM S B, et al. New approach to generalized two-dimensional correlation spectroscopy. 1: combination of principal component analysis and two-dimensional correlation spectroscopy [J]. Appl. Spectrosc., 2002, 56(12):1562-1567.
    [93] GIANNI S, IVARSSON Y, JMETH P, et al. Identification and characterization of protein folding intermediates [J]. Biophys. Chem., 2007, 128: 105-113.
    [94] ENGLANDER S W. Protein folding intermediates and pathways studied by hydrogen exchange [J]. Annu. Rev. Biophys. Biomol. Struct., 2000, 29:213-238.
    [95] KITAHARA R, YAMADA H, AKASAKA K. Two folded conformers of ubiquitin revealed by high-pressure NMR [J]. Biochemistry, 2001, 40: 13556-13563.
    [96] ROYER C A. Probing Protein Folding and Conformational Transitions with Fluorescence [J]. Chem. Rev., 2006, 106: 1769-1784.
    [97] RODER H, MAKI K, CHENG H, Early Events in Protein Folding Explored by Rapid Mixing Methods [J]. Chem. Rev., 2006, 106: 1836-1861.
    [98] LATYPOV R F, HARVEY T S, LIU D, et al. Biophysical characterization of structural properties and folding of interleukin-1 receptor antagonist [J]. J. Mol. Biol., 2007, 368: 1187-1201.
    [99] FABIAN H, GAST K, LAUE M, et al. Early stages of misfolding and association ofβ2-microglobulin: insights from infrared spectroscopy and dynamic light scattering [J]. Biochemistry, 2008, 47: 6895-6906.
    [100] AUSILI A, SCIRèA, DAMIANI E, et al. Temperature-induced molten globule-like state in human R1-acid glycoprotein: an infrared spectroscopic study [J]. Biochemstry, 2005, 44:15997-16006.
    [101] STELEA S, KEIDERLING T A. Pretransitional structural changes in the thermal denaturation of ribonuclease S and S protein [J]. Biophys. J, 2002, 83: 2259-2269.
    [102] STELEA S, PANCOSKA P, KEIDERLING T A. Thermal unfolding of ribonuclease A in phosphate at neutral pH: deviations from the two state model [J]. Protein Sci., 2001, 10: 970-978.
    [103] ZHUANG X, RIEF M. Single-molecule folding [J]. Curr. Opin. Struct. Biol., 2003, 13(1): 88-97.
    [104] SELVIN P R. The renaissance of fluorescence resonance energy transfer [J]. Nat. Struct. Biol., 2000, 7(9): 730-734.
    [105] CLAUSEN-SCHAUMANN H, SEITZ M, KRAUTBAUER R, et al. Force spectroscopy with single bio-molecules [J]. Curr. Opin. Chem. Biol., 2000, 4(5): 524-530.
    [106] LI L, HUANG H H, BADILLA C L, et al. Mechanical unfolding intermediates observed by single-molecule force spectroscopy in a fibronectin type III module [J]. J. Mol. Biol., 2005, 345(4):817-826.
    [107] MARSZALEK P E, LU H, LI H, et al. Mechanical unfolding intermediates in titin modules [J]. Nature, 1999, 402(6757):100-103.
    [108] CECCONI C, SHANK E A, BUSTAMANTE C, et al. Direct observation of the three-state folding of a single protein molecule [J]. Science, 2005, 309:2057-2060.
    [109] GAO M, CRAIG D, LEQUIN O, et al. Structure and functional significance of mechanically unfolded fibronectin type III1 intermediates [J]. Proc. Natl. Acad. Sci. USA, 2003, 100(25): 14784-14789.
    [110] SCHLIERF M, LI H, FERNANDEZ J M. The unfolding kinetics of ubiquitin captured with single-molecule force-clamp techniques [J]. Proc. Natl. Acad. Sci. USA, 2004, 101(19): 7299-7304.
    [111] MAITY H, MAITY M, KRISHNA M M, et al. Protein folding: the stepwise assembly of foldon units [J]. Proc. Natl. Acad. Sci. USA, 2005, 102(13): 4741-4746.
    [112] HUYNH T, SMITH J C, SANSON A. Protein unfolding transitions in an intrinsically unstable annexin domain: molecular dynamics simulation and comparison with nuclear magnetic resonance data [J]. Biophys. J., 2002, 83(2): 681-698.
    [113] KAVITHA M, SWAMY M J. Spectroscopic and differential scanning calorimetric studies on the unfolding of Trichosanthes dioica seed lectin. Similar modes of thermal and chemical denaturation [J]. Glycoconj J, 2009, DOI 10.1007/s10719-009-9228-y.
    [114] BOND C J, WONG K B, CLARKE J, et al. Characterization of residual structure in the thermally denatured state of barnase by simulation and experiment: description of the folding pathway [J]. Proc. Natl Acad. Sci. USA, 1997, 94(25):13409-13413.
    [115] BROOKS III C L, GRUEBELE M, ONUCHIC J N. Chemical physics of protein folding [J]. Proc. Natl. Acad. Sci. USA, 1998, 95(19):11037-11038.
    [116] GSPONER J, HOPEARUOHO H, WHITTAKER S B, et al. Determination of an ensemble of structures representing the intermediate state of the bacterial immunity protein Im7 [J]. Proc. Natl. Acad. Sci. USA, 2006, 103(1): 99-104.
    [117] DIXON R D, CHEN Y, DING F, et al. New insights into FAK signaling and localization based on detection of a FAT domain folding intermediate [J]. Structure 2004, 12(12): 2161-2171.
    [118] MITTERMAIER A, KAY L E. New tools provide new insights in NMR studies of protein dynamics [J]. Science, 2006, 312(5771): 224-228.
    [119] KORZHNEV D M, SALVATELLA X, VENDRUSCOLO M, et al. Low-populated folding intermediates of Fyn SH3 characterized by relaxation dispersion NMR [J]. Nature, 2004, 430(6999): 586-590.
    [120] MERKLEY E D, BERNARD B, DAGGETT V. conformational changes below the Tm: molecular dynamics studies of the thermal pretransition of ribonuclease A [J]. Biochemistry, 2008, 47:880-892.
    [121] COTESTA S, TAVERNELLI I, LORIO E E D. Dynamics of RNase-A and S-protein: a molecular dynamics simulation of the transition toward a folding intermediate [J]. Biophys. J., 2003, 85:2633-2640.
    [122] YAN Y B, ZHANG J, HE H W et al. Oligomerization and aggregation of bovine pancreatic ribonuclease A: characteristic events observed by FTIR spectroscopy [J]. Biophys. J, 2006, 90(7):2525-2533.
    [123] YAN Y B, WANG Q, HE H W, et al. Two-dimensional infrared correlation spectroscopy study of sequential events in the heat-induced unfolding and aggregation process of myoglobin [J]. Biophys. J. 2003, 85(3): 1959-1967.
    [124] SCHULTZ C P, FABIAN H, MANTSCH H H. Two-dimensional mid-IR and near-IR correlation spectra of ribonuclease A: using overtones and combination modes to monitor changes in secondary structure [J]. Biospectroscopy, 1998, 4: S19-S29.
    [125] CZARINIK-MATUSEWICZ B, MURAYAMA K, WU Y, et al. Two-dimensional attenuated total reflection/infrared correlation spectroscopy of adsorption-induced and concentration-dependent spectral variations ofβ-Lactoglobulin in aqueous solutions [J]. J. Phys. Chem. B, 2000, 104(32):7803-7811.
    [126] YUAN B, MURAYAMA K, WU Y, et al. Temperature-dependent near-infrared spectra of bovine serum albumin in aqueous solutions: spectral analysis by principal component analysis and evolving factor analysis [J]. Appl. Spectrosc., 2003, 57(10):1223-1229.
    [127] MURAYAMA K, WU Y, CZARNIK-MATUSEWICZ B, et al. Two-dimensional/attenuated total reflection infrared correlation spectroscopy studies on secondary structural changes in human serum albumin in aqueous solutions: pH-dependent structural changes in the secondary structures and in the hydrogen bondings of side chains [J]. J. Phys. Chem. B., 2001, 105(20):4763-4769.
    [128] WU Y, CZARNIK-MATUSEWICZ B, MURAYAMA K, et al. Two-Dimensional Near-Infrared Spectroscopy Study of Human Serum Albumin in Aqueous Solutions: Using Overtones and Combination Modes to Monitor Temperature-Dependent Changes in the Secondary Structure [J]. J. Phys. Chem. B, 2000, 104 (24): 5840-5847.
    [1] MEERSMAN F, HEREMANS K. Temperature-induced dissociation of protein aggregates: accessing the denatured state [J]. Biochemistry, 2003, 42(48):14234-14241.
    [2] WONG P T T, MOFFAT D J. A new internal pressure calibrant for high-pressure infrared spectroscopy of aqueous systems [J]. Appl. Spectrosc., 1989, 43(7):1279-1281.
    [3] WANG Y, MURAYAMA K, MYOJO Y, et al. Two-dimensional fourier transform near-infrared spectroscopy study of heat denaturation of ovalbumin in aqueous solutions [J]. J.Phys.Chem. B, 1998, 102: 6655-6662.
    [1] MATAGNE A, JAMIN M, CHUNG E W, et al. Thermal unfolding of an intermediate is associated with non-Arrhenius kinetics in the folding of hen lysozyme [J]. J. Mol. Biol., 2000, 297 (1): 193-210.
    [2] RADFORD S E, DOBSON C M. From computer simulations to human disease: emerging themes in protein folding [J]. Cell, 1999, 97(3): 291-298.
    [3] DOBSON C M. Protein Folding and Misfolding [J]. Nature, 2003, 426:884-890.
    [4] WLODAWER A, SVENSSON L A, SJ?LIN L, et al. Biochemistry, Structure of phosphate-free ribonuclease A refined at 1.26 A. 1988, 27(8): 2705-2717.
    [5] KORADI R, BILLETER M, W?THRICH K. MOLMOL: a program for display and analysis of macromolecular structures [J]. J. Mol. Graphics, 1996, 14:51-55.
    [6] ANFINSEN C B. Principles that govern the folding of protein chains [J]. Science, 1973, 181(96): 223-230.
    [7] WLODAWER A, BORKAKOTI N, MOSS D S, et al. Comparison of two independently refined models of ribonuclease-A [J]. Acta Cryst., 1986, B42(4): 379-387.
    [8] DOBSON C M, ?ALI A, KARPLUS M. Proteinfaltung aus theoretischer und experimenteller Sicht [J]. Angew. Chem. Int. Ed., 1998, 110(7): 908-935.
    [9] DILL K A, CHAN H S. From Levinthal to pathways to funnels [J]. Nat. Struct. Biol., 1997, 4(1): 10-19.
    [10] DENISOV V P, HALLE B. Thermal denaturation of ribonuclease A characterized by water 17O and 2H magnetic relaxation dispersion [J]. Biochemistry, 1998, 37(26): 9595-9604.
    [11] RAINES R T. Ribonuclease A [J]. Chem. Rev., 1998, 98: 1045-1065.
    [12] STELEA S, PANCOSKA P, KEIDERLING T A. Thermal unfolding of ribonuclease A in phosphate at neutral pH: deviations from the two state model [J]. Protein Sci., 2001, 10: 970-978.
    [12] PRIVALOV P L. Intermediate states in protein folding [J]. J. Mol. Biol., 1996, 258(5):707-725.
    [13] NAVON A, ITTAH V, LAITY J H, et al. Local and long-range interactions in the thermal unfolding transition of bovine pancreatic ribonuclease A [J]. Biochemistry, 2001, 40(1): 93-104.
    [14] NORONHA M, LIMA J C, PACI E, et al. Tracking local conformational changes of ribonuclease A using picosecond time-resolved fluorescence of the six tyrosine residues [J]. Biophys. J, 2007, 92(12):4401-4414.
    [15] GALLY J A, EDELMAN G M. The effect of temperature on the fluorescence of some aromatic amino acids and proteins [J]. Biochim. Biophys. Acta, 1962, 60:499-509.
    [16] SWADESH J K, MUI PW, SCHERAGA H A. Thermodynamics of the quenching of tyrosyl fluorescence by dithiothreitol [J]. Biochemistry, 1987, 26(18):5761-5769.
    [17] WLODAWER A, SVENSSON L A, SJ?LIN L, et al. Structure of phosphate-free ribonuclease A refined at 1.26 A [J]. Biochemistry, 1988, 27(8):2705-2717.
    [18] SCHULTZ C P, FABIAN H, MANTSCH H H. Two-dimensional mid-IR and near-IR correlation spectra of ribonuclease A: using overtones and combination modes to monitor changes in secondary structure [J]. Biospectroscopy, 1998, 4: S19-S29.
    [19] FABIAN H, M?NTELE W. Infrared spectroscopy of proteins [M]// Chalmers J M, Griffiths P R, Handbook of Vibrational Spectroscopy, Chichester: John Wiley and Sons, 2002, 5:3399-3426.
    [20] FABIAN H, MANTSCH H H. Ribonuclease A revisited: infrared spectroscopic evidence for lack of native-like secondary structures in the thermally denatured state [J]. Biochemistry, 1995, 34(41):13651-13655.
    [21] N?PPERT A, GAST K, MüLLER-FROHNE M, et al. Reduced-denatured ribonuclease A is not in a compact state [J]. FEBS Lett., 1996, 380(1-2):179-182.
    [22] LI Y J, ROTHWARF D M, SCHERAGA H A. Mechanism of reductive protein unfolding [J]. Nat. Struct. Biol., 1995, 2(6):489-494.
    [23] SHIMOTAKAHARA S, RIOS C B, LAITY J H, et al. NMR structural analysis of an analog of an intermediate formed in the rate-determining step of one pathway in the oxidative folding of bovine pancreatic ribonuclease A: automated analysis of 1H, 13C, and 15N resonance assignments for wild-type and [C65S, C72S] mutant forms [J]. Biochemistry, 1997, 36(23):6915-6929.
    [24] TALLURI S, ROTHWARF D M, SCHERAGA H A. Structural characterization of a three-disulfide intermediate of ribonuclease A involved in both the folding and unfolding pathways [J]. Biochemistry, 1994, 33(34):10437-10439.
    [25] DENISOV V P, HALLE B. Thermal denaturation of ribonuclease A characterized by water 17O and 2H magnetic relaxation dispersion [J]. Biochemistry, 1998, 37(26):9595-9604.
    [26] ZHANG J, PENG X, JONAS A, et al. NMR study of the cold, heat, and pressure unfolding of ribonuclease A [J]. Biochemistry, 1995, 34(27):8631-8641.
    [27] TAMURA Y, GEKKO K. Compactness of thermally and chemically denatured ribonuclease A as revealed by volume and compressibility [J]. Biochemistry, 1995, 34(6):1878-1884.
    [28] YAN Y B, ZHANG J, HE H W et al. Oligomerization and aggregation of bovine pancreatic ribonuclease A: characteristic events observed by FTIR spectroscopy [J]. Biophys. J, 2006, 90(7):2525-2533.
    [29] TAKEDA N, KATO M, TANIGUCHI Y. Pressure- and thermally-induced reversible changes in the secondary structure of ribonuclease A studied by FT-IR spectroscopy [J]. Biochemistry, 1995, 34(17):5980-5987.
    [30] MEERSMAN F, HEREMANS K. High pressure induces the formation of aggregation-prone states of proteins under reducing conditions [J]. Biophys. Chem., 2003, 104(1):297-304.
    [31] WU Y, MURAYAMA K, OZAKI Y, Two-dimensional infrared spectroscopy and principle component analysis studies of the secondary structure and kinetics ofhydrogen-deuterium exchange of human serum albumin [J]. J. Phys. Chem. B, 2001, 105(26):6251-6259.
    [32] NODA I, OZAKI Y. Two-Dimensional Correlation Spectroscopy [M] Chichester: John Wiley, 2004.
    [33] CZARINIK-MATUSEWICZ B, MURAYAMA K, WU Y. et al. Two-dimensional attenuated total reflection/infrared correlation spectroscopy of adsorption-induced and concentration-dependent spectral variations ofβ-lactoglobulin in aqueous solutions [J]. J. Phys. Chem. B, 2000, 104(32):7803-7811.
    [1]游长江,卢雪芳,李嫕等.钻石对顶砧(Diamond Anvil Cell, DAC)高压产生技术及在高压条件下的光物理和光化学研究[J].感光科学与光化学, 2002, 20(3): 197-203.
    [2] HEMELEY R J. Effects of high pressure on molecules [J]. Annu. Rev. Phys. Chem. 2000, 51:763-800.
    [3] DUNSTAN D J, SPAIN I L. The technology of diamond anvil high-pressure cells: I. Principles, design and construction [J]. J. Phys. E.: Sci. Instrum., 1989, 22: 913-923.
    [4] SPAIN I L, DUNSTAN D J. The technology of diamond anvil high-pressure cells: II. Operation and use [J]. J. Phys. E.: Sci. Instrum., 1989, 22: 923-933.
    [5] JAYARAMAN A. Diamond anvil cell and high-pressure physical investigations [J]. Rev. Mod. Phys. 1983, 55(1): 65-108.
    [6]韩永昊.金刚石对顶砧上原位电导率测量方法[D].长春:吉林大学超硬材料国家重点实验室, 2005.
    [7] LAWSON A W, TANG T Y. A Diamond bomb for obtaining powder pictures at high pressures [J]. Rev. Sci. Instrum., 1950, 21(9): 815.
    [8] JAMIESON J C, LAWSON A W, NACHTRIEB N D. New device for obtaining x-ray diffraction patterns from substances exposed to high pressure [J]. Rev. Sci. Instrum., 1959, 30: 1016-1019.
    [9] WEIR C E, LIPPINCOTT E R, VALKBURG A V, et al. Infrared studies in the 1-to 15-micron region to 30,000 atmospheres [J]. J. Res. Natl. Bur. Stand. Sect., 1959, A63: 55-62.
    [10]陈晋阳,张红,肖万生等.金刚石压腔高温高压原位谱学研究的评述[J].光谱实验室, 2004, 21(2): 209-216.
    [11]孙樯,郑海飞.金刚石压腔(DAC)实验技术[J].地学前缘, 2005, 12(1): 131-136.
    [12] HUANG W L, OTTEN G A. Oil generation kinetics determined by DAC-IR/FL pyrolysis: technique development and preliminary results [J]. Org. Geochem., 1998, 29:1119-1137.
    [13] HU S M, ZHANG R H, ZHANG X T. A study of near and supercritical fluids using diamond anvil cell and in-situ FTIR spectroscopy [J]. Acta Geol. Sinica, 2000, 74:412-417.
    [14]郑海飞,shen A,张明等.压力0.1~800 MPa下液态水性质的红外光谱研究[J].自然科学进展, 2002, 12(6): 662-664.
    [15] SCHOONOVER J R, DATTELBAUM D M, OSBORN J C et al. Pressure-dependent fourier transform infrared spectroscopy of a poly (ester urethane) [J]. Spectrochimica Acta Part A, 2003, 59(2): 309-319.
    [16] HAYASHI R. Trends in high pressure bioscience and biotechnology: proceedings First International Conference on High Pressure Biosocience and Biotechnology (HPBB-2000), Kyoto, Japan, November 26-30 2000[C]. Amsterdam: Elsevier, 2002.
    [17] DZWOLAK W, KATO M, TANIGUCHI Y. Fourier transform infrared spectroscopy in high-pressure studies on proteins [J]. Biochim. Biophys. Acta., 2002, 1595(1-2):131-144.
    [18] SMELLER L, MEERSMAN F, HEREMANS K. Stable misfolded states of human serum albumin revealed by high-pressure infrared spectroscopic studies [J]. Eur. Biophys. J, 2008, 37(7):1127-1132.
    [19] RIBóM, FONT J, BENITO A, et al. Pressure as a tool to study protein-unfolding/refolding processes: the case of ribonuclease A [J]. Biochim. Biophys. Acta, 2006, 1764:461-469.
    [20] THAKUR B R, NELSON P E. High-pressure processing and preservation of food [J]. Food Rev. Int., 1998, 14:427-447.
    [21] YUSTE J, CAPELLAS M, PLA R, et al. High pressure processing for food safety and preservation: a review [J]. J. Rapid Methods Autom. Microbiol., 2001, 9: 1-10.
    [22] MOZHAEV V, HEREMANS K, FRANK J, et al. Exploiting the effects of high hydrostatic pressure in biotechnological applications [J]. Tibtech, 1994, 12: 493-501.
    [23] MOZHAEV V, HEREMANS K, FRANK J, et al. High pressure effects on protein structure and function [J]. Prot. Struc. Funct. Gene., 1996, 24: 81-91.
    [24] BUCK M, RADFORD S E, DOBSON C M. Amide hydrogen exchange in a highly denatured state. Hen egg-white lysozyme in urea [J]. J Mol. Biol., 1994, 237(3): 247-254.
    [25] MAYO S L, BALDWIN R L. Guanidinium chloride induction of partial unfolding in amide proton exchange in RNase A [J]. Science, 1993, 262:873-876.
    [26] DOBSON C M, SALI A, KARPLUS M. Protein faltung aus theoretischer und experimenteller Sicht [J]. Angew Chem., 1998, 110:908-935.
    [27] KIM P S, BALDWIN R L. Specific intermediates in the folding reactions of small proteins and the mechanism of protein folding [J]. Annu. Rev. Biochem., 1982, 51: 459-489.
    [28] KIM P S, BALDWIN R L. Intermediates in the folding reactions of small proteins [J]. Annu. Rev. Biochem., 1990, 59: 631-660.
    [29] RUAN K, BALNY C. High pressure static fluorescence to study macromolecular structure-function [J]. Biochim Biophys Acta., 2002, 1595(1-2): 94-102.
    [30] SILVA J L, FOGUEL D, ROYER C A. Pressure provides new insights into protein folding, dynamics and structure [J]. Trends Biochem. Sci., 2001, 26(10): 612-618.
    [31] HERBERHOLD H, WINTER R. Temperature- and pressure-induced unfolding and refolding of ubiquitin: a static and kinetic Fourier transform infrared spectroscopy study [J]. Biochemistry, 2002, 41(7): 2396-2401.
    [32] MEERSMAN F, DOBSON C M, HEREMANS K. Protein unfolding, amyloid fibril formation and configurational energy landscapes under high pressure conditions [J]. Chem. Soc. Rev., 2006, 35(10): 908-917.
    [33] SILVA J L, WEBER G. Pressure stability of proteins [J]. Annu. Rev. Phys. Chem. 1993, 44:89-113.
    [34] RAVIKUMAR B, SARKAR S, BERGER Z, et al. The roles of the ubiquitin-proteasome and autophagy-lysosome pathways in huntington’s disease and related conditions [J]. Clin. Neurosci. Res., 2003, 3:141-148.
    [35] VIJAY-KUMAR S, BUGG C E, WILKINSON K D, et al. Three-dimensional structure of ubiquitin at 2.8 A resolution [J]. Proc. Natl. Acad. Sci. USA, 1985, 82(11): 3582-3585.
    [36] VIJAY-KUMAR S, BUGG C E, COOK W J. Structure of ubiquitin refined at 1.8 A resolution [J]. J. Mol. Biol. 1987, 194(3): 531-544.
    [37] LOVE S G, MUIR T W, RAMAGE R, et al. Synthetic, structural and biological studies of the ubiquitin system: synthesis and crystal structure of an analogue containing unnatural amino acids [J]. Biochem. J, 1997, 323: 727-734.
    [38] KITAHARA R, YAMADA H, AKASAKA K. Two folded conformers of ubiquitin revealed by high-pressure NMR [J]. Biochemistry, 2001, 40(45): 13556-13563.
    [39] KRANTZ B A, SOSNICK T R. Distinguishing between two-State and three-state models for ubiquitin folding [J]. Biochemistry, 2000, 39: 11696-11701.
    [40] KHORASANIZADEH S, PETERS I D, BUTT T R, et al. Folding and stability of a tryptophan-containing mutant of ubiquitin [J]. Biochemistry, 1993, 32: 7054-7063.
    [41] GLADWIN S T, EVANS P A. Structure of very early protein folding intermediates: new insights through a variant of hydrogen exchange labelling [J]. Fold Des., 1996, 1(6): 407-417.
    [42] IRB?CK A, MITTERNACHT S, MOHANTY S. Dissecting the mechanical unfolding of ubiquitin [J]. Proc. Natl. Acad. Sci. USA., 2005, 102(38): 13427-13432.
    [43] WENT H M, BENITEZ-CARDOZA C G, JACKSON S E. Is an intermediate state populated on the folding pathway of ubiquitin [J]? FEBS Letters 2004, 567: 333-338.
    [44] KHORASANIZADEH S, PETERS I D, RODER H. Evidence for a three-state model of protein folding from kinetic analysis of ubiquitin variants with altered core residues [J]. Nature Struct. Biology, 1996, 3: 193-205.
    [45] FABIAN H, M?NTELE W. Infrared spectroscopy of proteins [M]// Chalmers J M, Griffiths P R, Handbook of Vibrational Spectroscopy, Chichester: John Wiley and Sons, 2002, 5: 3399-3426.
    [46] BARTH A, ZSCHERP C. What vibrations tell us about proteins [J]. Q. Rev. Biophys., 2002, 35: 369-430.
    [47] NODA I, OZAKI Y. Two-Dimensional Correlation Spectroscopy [M] Chichester: John Wiley, 2004.
    [48] NODA I. Advances in two-dimensional correlation spectroscopy [J]. Vib. Spectrosc., 2004, 36(2): 143-165.
    [49] SMELLER L, HEREMANS K. 2D FT-IR spectroscopy analysis of the pressure-induced changes in proteins [J]. Vib. Spectrosc., 1999, 19:375-378.
    [50] SMELLER L, RUBENS P, FRANK J, et al. Two dimensional fourier-transform infrared correlation spectroscopy study of the high-pressure tuning of proteins [J]. Vib. Spectrosc., 2000, 22:119-125.
    [51] DZWOLAK W, KATO M, TANIGUSHI Y. Fourier transform infrared spectroscopy in high-pressure studies on proteins [J]. Biochim. Biophys. Acta., 2002, 1595:131-144.
    [52] JACOBSEN S, S?NDERGAARD I, M?LLER B, et al. A chemometric evaluation of the underlying physical and chemical patterns that support near infrared spectroscopy of barley seeds as a tool for explorative classification of endosperm genes and gene combinations [J]. J. Cereal Sci. 2005, 42: 281-299.
    [53] HEREMANS K, SMELLER L. Protein structure and dynamics at high pressure [J]. Biochim. Biophys. Acta 1998, 1386: 353-370.
    [54] WU Y, MURAYAMA K, OZAKI Y, Two-dimensional infrared spectroscopy and principle component analysis studies of the secondary structure and kinetics of hydrogen-deuterium exchange of human serum albumin [J]. J. Phys. Chem. B 2001, 105(26): 6251-6259.
    [55] DONG A, HYSLOP R M, PRINGLE D L. Differences in conformational dynamics of ribonucleases A and S as observed by infrared spectroscopy and hydrogen-deuterium exchange [J]. Arch. Biochem. Biophys., 1996, 333(1): 275-281.
    [56] SEEMANN H, WINTER R, ROYER C A. Volume, expansivity and isothermal compressibility changes associated with temperature and pressure unfolding of Staphylococcal nuclease [J]. J. Mol. Biol., 2001, 307(4): 1091-1102.
    [57] SCHLIERF M, LI H, FERNANDEZ J M. The unfolding kinetics of ubiquitin captured with single-molecule force-clamp techniques [J]. PNAS, 2004, 101(19): 7299-7304.
    [58] WENT H M, JACKSON S E. Ubiquitin folds through a highly polarized transition state [J]. Protein Eng. Des. Sel. 2005, 18(5): 229-237.
    [59] HARDING M M, WILLIAMS D H, WOOLFSON D N. Characterization of a partially denatured state of a protein by two-dimensional NMR: reduction of the hydrophobic interactions in ubiquitin [J]. Biochemistry, 1991, 30: 3120-3128.
    [60] ALONSO D, DAGGETT V. Molecular Dynamics Simulations of Protein Unfolding and Limited Refolding: Characterization of Partially Unfolded States of Ubiquitin in 60% Methanol and in Water [J]. J. Mol. Biol. 1995, 247: 501-520.
    [61] PASCHEK D, GNANAKARAN S, GARCIA A E. Simulations of the pressure and temperature unfolding of anα-helical peptide [J]. Proc. Natl. Acad. Sci. USA 2005, 102(19): 6765-6770.
    [62] HUMMER G, GARDE S, GARCIA A E et al. The pressure dependence of hydrophobic interactions is consistent with the observed pressure denaturation of proteins [J]. Proc. Natl. Acad. Sci. USA, 1998, 95(4): 1552-1555.
    [63] KITAHARA R, AKASAKA K. Close identity of a pressure-stabilized intermediate with a kinetic intermediate in protein folding [J]. Proc. Natl. Acad. Sci. USA, 2003, 100(6): 3167-3172.
    [64] DAY R, GARCíA A E. Water penetration in the low and high pressure native states of ubiquitin [J]. Proteins, 2008, 70(4): 1175-1184.
    [65] ROYER C A. Insight into the role of hydration in protein structure and stability obtained through hydrostatic pressure studies [J]. Braz. J. Med. Biol. Res. 2005, 38(8): 1167-1173.
    [66] HEREMANS K. Protein dynamics: hydration and cavities [J]. Braz. J. Med. Biol. Res. 2005, 38(8): 1157-1165.
    [67] COLLINS M D, HUMMER G, QUILLIN M L, et al. Cooperative water filling of a nonpolar protein cavity observed by high pressure crystallography and simulation [J]. Proc. Natl. Acad. Sci. USA, 2005, 102(46): 16668-16671.

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