超嗜热古菌Aeropyrum pernix K1酰基肽水解酶/酯酶N-末端区域稳定化机制研究
详细信息    本馆镜像全文|  推荐本文 |  |   获取CNKI官网全文
摘要
研究N-末端区域对酶稳定性的影响,不但能够加深了解酶的稳定化机制,而且对促进蛋白质分子设计和工程酶的应用具有重要意义。
    来源于超嗜热古菌Aeropyrum pernix K1基因APE1547的重组蛋白表现酰基肽水解酶和酯酶的催化活性,其生物学稳定性极好。晶体结构分析表明,该酶由两个结构域组成。通过同源结构比较,发现N-末端区域具有连接两个结构域的作用,为揭示N-末端结构对酶活性及稳定性的影响,本论文构建了N-末端氨基酸缺失和两对盐桥消除的系列突变体。动力学、热力学及结构信息学分析揭示出,N-末端增加了局部稳定域的数量并增强了稳定域的刚性,阐明了其可能的区域稳定化机制。本研究为酶的稳定化设计提供了理论依据。
Phylogenetic tree and circumstancial evidence suggest thehyperthermophiles, including archaea and bacteria, were the first life-forms tohave arisen on earth. Hyperthermophilic enzyme can therefore serve as modelsystems in understanding enzyme evolution, molecular mechanisms fro proteinthermostability, and the upper temperature limit for enzyme function. Thisknowledge can lead to the development of new and more efficient proteinengineering strategies and a wide range of biotechnological applications.
    Thermostability at high temperatures is an inherent property of hyperthermophilicenzymes. Enough experimental evidence (e.g., sequence, mutagenesis, structure, andthermodynamics) has been accumulated on hyperthermophilic proteins in recent yearsto try to discover new factors which are responsible for the remarkable stability ofhyperthermophilic proteins. Eventhough, it seems that no single mechanism isresponsible for the remarkable stability of hyperthermophilic proteins, the factors suchas surface salt bridge networks, solvent-exposed hydrophobic surface, and anchoring of“loose ends” (i.e., the N and C termini and loops) to the protein surface seem to beinstrumental in hyperthermophilic protein thermostability. Some researcher accountthat about half proteins in PDB bank were found to have their two terminals interactedeach other. Some experimental evidence further suggested that protein stability is
    inflected by terminal extention or truncation, and the stability will decrease when theinteractions between the terminal and the structure were destroyed. So, to investigatethe effect of N-terminal on the stabilization of hyperthermophilic enzyme willnot only enhance our knowledge on mechanisms of protein stabilization, butalso contribute on resional design of protein stabilization.The recombinant protein APE1547 from the thermophilic archaeonAeropyrum pernix K1 is characterized as acylpeptide hydrolase and possessesboth acylpeptide hydrolase and esterase activity. APE1547 shows extremelyhigh thermalstability and solvent resistance. Recently, the crystal structure ofAPE1547 was determined. Crystal structure analysis reveals structural homologywith members of the POP family, which contain β-propeller domain andα/β-hydrolase domain. An N-terminal extension was found to connect thehydrolase domain. The possible role of the N-terminal extension is believed toprovide stability of the circular structure of the propeller by covalently linking itto the peptidase domain. By structure superposition, we found the N-terminalextension of APE1547 anchored tightly on the terminal region by hydrophobicinteractions, hydrogen bonds and salt bridges Therefore, it is speculated thatN-terminal of APE1547 may play a significance role on the protein stability.In order to investigate the stability mechanisms of N-terminal of APE1547,we constructed mutants including N-terminal truncated mutants (21del and10del) and salt bridges disrupted mutants (D15A, R18A and D15A/R18A). Thecatalytic property and stability of the wild-type and mutants were compared indetails.The optimum temperature of wild type is 95?C, by contrast with wild-type,the optimum temperatures of mutants 21del, D15A, R18A and D15A/R18A aredecreased to 92.5?C and 77.5?C, respectively. The catalytic rate of mutant 21delis slightly higher than wild type at low temperature. The optimum pH is 8.0 for
    wild type and 8.5 for mutant 21del, and their substrate specificities areconsistent. The thermodynamic parameters of activity were calculated. Theentropy and enthalpy of wild type are both lower than mutants, which suggestthe molecular motion lose of wild type is higher than mutants during the ES*transition state. Structure analysis of mutant 21del indicated that the diameter ofcavity which is believe to be the route of the substrate approaching the activesite located between the two domains enlarged. The hydrogen bonds around theactive site are decreased remarkably. These results suggested that N-termianlmutate increased the flexibility of active site region.Thermal denaturation was determined by substrate activation, CD,tryptophan fluorescence, hydrophobic fluorescent probe ANS and differentialscanning calorimetry (DSC) methods. The thermal inactivation constant ofmutants 21del, 10del, D15A, R18A and D15A/R18A at 85oC is 17, 4.9, 2.6, 3.8and 1.6 times to wild type, and the free energy is decreased 8.5, 4.3, 2.9, 4.0 and1.5 kJ/mol, respectively. The inactivation process is believed to be drived byentropy. Based on the CD, tryptophan fluorescence, and hydrophobicfluorescent probe ANS detection, the inactivation was occurs on the tertiarystructure level within subtle rearrangement. As recorded by DSC, Thecalculated total enthalpic changes (∑△Hcal) are 795.3, 345.0, 522.7, 523.9 and528.1kcal/mol for WT, mutant 21del, D15A, R18A and D15A/R18A,respectively. Deconvolution of the excess heat capacity (Cp) functions revealedfive subsequent transitions for APE1547, which suggested the WT contains 5calorific stable domains, while the mutants 21del, 10del, D15A and R18Acontains 2, 3, 4 and 4, respectively. Even though, the muant D15A/R18Acontains the same number calorific stable domains compared with wild type,the stability decreased about 33.6% compared to wild type calculated by totalenthalpic changes. These results above suggested that the N-terminal of
    APE1547 may enhance the stability by increasing the numbers of calorificstable domains or by increasing the intensity of each calorific stable domains.The changes in the activity and the conformation of wild-type and mutantwere determined during unfolding by guanidine hydrochloride (Gdn-HCl).Activities of wild type and mutants 21del, 10del were completely loss at 2.6M,1M and 1.4M Gdn-HCl, respectively. The activity losing is well cooperatedwith fluorescence intensity decreasing. Three-state model and four-state modelwere used to fit the unfolding process. One intermediate was found in theunfolding process of wild type and mutants D15A, R18A and D15A/R18A,while two intermediates for mutants 21del and 10del. N-terminal truncation andsalt bridge disrupting mainly decrease the stability of local region whichcorrelated active site and α/β hydrolase domain of APE1547. The free energy ofmutants 21del, 10del, D15A, R18A and D15A/R18A were decreased about 15.5,5.3, 0.3, 3.5 and 3.9 kJ/mol. Refolding experiment indicated that the unfoldingprocess of wild type and mutants D15A, R18A and D15A/R18A is reversiableduring native to the intermediate, but for the process from intermediate tounfolding state seems to irreversible, for the activity can not be recovered. Theactivity of mutant 21del can not be recovered in all concentration of Gdn-HCl.The results suggested that the N-terminal may be play important role inAPE1547 folding in vitro.In conclusion, we provide direct evidence that N-terminal of APE1547 fromthe hyperthermophilic archaeon Aeropyrum pernix K1 plays an important rolein the protein stability. We constructed a series of mutants based on the resultsof structure alignment. Enzyme characters and unfolding process which isinduced by thermal and Gdn-HCl were mensurated with CD and fluorescencespectrum technical. Combining the results gained from enzymology, kinetics ofthermal inactivation, thermodynamics and protein structure analysis, we
    confirmed that the N-terminal of APE1547 participates in forming localstabilized regions by salt bridges and hydrophobic interactions. Through thisstrategy, the two domains of APE1547 pack compactly, and the stabilityenhanced by increasing the numbers of calorific stable domains or by increasingthe intensity of each calorific stable domains. The increased local regionstability further protected the flexible α/β hydrolase against denaturants. Inaddition, evidence suggests that N-terminal has taken part in the folding processof active site. This study amplified our understanding on high stability ofmulti-domain thermophilic protein and made contribution of rational design ofprotein stabilization.
引文
[1] Rothschild L. J., Mancinelli R. L., Life in extreme environments, Nature, 2001, 409: 1092-1101.
    [2] Javaux E. J., Extreme life on Earth—past, present and possibly beyond, Research in Microbiology, 2006,157:37–48.
    [3] 马延和,新的生命形式-极端微生物,微生物学通报,1999,26.
    [4] Aguilar A., Ingemansson T., Magnien E., Extremophile microorganisms as cell factories: support from the European Union, Extremophiles, 1998, 2:367–373.
    [5] Fujiwara S., Extremophiles: developments of their special functions and potential resources, J. Bioscience and Bioengineering, 2002, 90:518-525.
    [6] Woese C. R., Kandler O., Wheelis M. L., Towards a natural system of organisms-proposal for the domains Archaea, Bacteria and Eukarya, Proc. Natl. Acad. Sci. USA, 1990, 87:4576-4579.
    [7] Woese C. R., and Fox G. E., Phylogenic structure of the prokaryotic domain: the primary phyla, Proc. Natl. Acad. Sci. USA, 1977, 74:5088-5099.
    [8] Fujiwara S., Okuyama S., and Imanaka T., The world of archaea: aenome analyis, evolution and thermostable enzyme, Gene, 1996, 179:165-170.
    [9] Iwabe N., Kuma K., Hasegawa M., and Osawa S., Evolutionary relationship of archaebacteria, eubacteria and eukaryotes interred from phylogenetic tree of duplicated genes, Proc. Natl. Acad. Sci.. USA, 1989, 86:9355-9359.
    [10] Barns S. M., Delwiche C. F., Palmer J. D., and Pace N. R., Perspectives on archaeal diversity, thermophily and monophyly from emvironmental rRNA sequence, Proc. Natl. Acad. Sci. USA, 1996, 93:9188-9193.
    [11] Huber H., Hohn M. J., Rachel R., Fuchs T., Wimmer V. C., and Stetter K. O., A new phylum of Archaea represented by a nanosized hyperthermophilic symbiont, Nature, 2002, 417:63-67.
    [12] Stetter K. O., Hyperthermophilic prokaryotes, FEMS Microbiol. Rev., 1996, 18:149-158.
    [13] Blochl E., Rachel R., Burggraf S., Hafenbradl D., Jannasch H. W., Stetter K. O, Pyrolobus fumarii, gen. and sp. nov., represents a novel group of archaea, extending the upper temperature limit for life to 113 oC, Extremophiles, 1997, 1:14-21.
    [14] 和致中,彭谦,陈俊英,高温菌生物学,科学出版社,2001年.
    [15] Warabayasi, Hino Y., Horikawa Y., et al.,Complete genome sequence of an aerobic hyper-thermophilic crenarchaeon, Aeropyrum pernix K1, DNA Res., 1999, 6:83-101,145-152.
    [16] Klenk H. P., Clayton R. A., Tomb J. F., et al.,The complete genome sequence of the hyperthermophilic, sulphate-reducing archaeon Archaeoglobus fulgidus, Nature, 1997, 390:364-370.
    [17] Slesarev, A. I., Mezhevaya, K. V., Makarova, K. S., et al., The complete genome of hyperthermophile Methanopyrus kandleri AV19 and monophyly of archaeal methanogens, Proc. Natl. Acad, Sci. USA, 2002, 99:4644-4649.
    [18] Huber H, Hohn M. J, Rachel R, Fuchs T, Wimmer V. C, Stetter K. O, A new phylum of Archaea represented by a nanosized hyperthermophilic symbiont., Nature, 2002, 417:27-28.
    [19] Fitz-Gibbon S. T., Ladner H., Kim U. J., Stetter K. O., Simon M. I., and Miller J. H. Genome sequence of the hyperthermophilic crenarchaeon Pyrobaculum aerophilum, Proc. Nat. Acad. Sci., 2002, 99:984-989.
    [20] Cohen G. N., Barbe V., Flament D., et al., An integrated analysis of the genome of the hyperthermophilic archaeon Pyrococcus abyssi, Mol. Microbiol., 2003, 47:1495-1512.
    [21] Kawarabayasi Y., Sawada M., Horikawa H., et al., Complete sequence and gene organization of the genome of a hyperthermophilic Archaebacterium, Pyrococcus horikoshii OT3. DNA Res. 1998, 5:55-76.
    [22] She Q., Singh R. K., Confalonieri F., Zivanovic Y., et al., The complete genome of the crenarchaeon Sulfolobus solfataricus P2., Proc. Natl. Acad. Sci. USA, 2001, 98:7835-7840.
    [23] Kawarabayasi Y., Hino Y., Horikawa H., Jin-no K., et al., Complete genome sequence of an aerobic thermoacidophilic crenarchaeon, Sulfolobus tokodaii strain., DNA Res., 2001, 8:123-140.
    [24] Deckert G., Warren P. V., Gaasterland T., Young W. G., et al., The complete genome of the hyperthermophilic bacterium Aquifex aeolicus, Nature, 1998, 392:353-358.
    [25] Bao Q., Tian Y, Li W., A complete sequence of the T. tengcongensis genome, Genome Res., 2002,, 12:689-700.
    [26] Nelson K.E., Clayton R.A., Gill S.R., Evidence for lateral gene transfer between Archaea and bacteria from genome sequence of Thermotoga maritime, Nature, 1999, 399:323-9.
    [27] Sako Y., Nomura N., Uchida A., Ishida Y., Morii H., Koga Y., Hoaki T., Murayama T., Aeropyrum pernix gen. nov., a novel Aerobic hyperthermophilic archaeon growing at temperature up to 100 ℃, J. Syst. Bacteriol. 1996, 6:1070-1077.
    [28] 王柏静,冯雁,王师钰,孔祥菊,曹淑桂,嗜热酶的特性及其应用,微生物学报,2002,42:259-262.
    [29] Bornscheuer U. T., Microbial carboxyl esterases: classification, properties and application in biocatalysis, FEMS Microbiol Rev., 2002, 26:73-81.
    [30] Bornscheuer U. T., Methods to increase enantioselectivity of lipases and esterases, Curr. Opin. Biotechnol., 2002, 13:543-547.
    [31] De Simone G., Menchise V., Manco G., Mandrich L., Sorrentino N., Lang D., Rossi M., Pedone C., The crystal structure of a hyper-thermophilic carboxylesterase from the archaeon Archaeoglobus fulgidus, J Mol Biol., 2001, 314:507-518.
    [32] Sehgal A. C., Callen W., Mathur E. J., Short J. M., Kelly R. M., Carboxylesterase from Sulfolobus solfataricus P1, Methods Enzymol., 2001, 330:461-471.
    [33] Hotta Y., Ezaki S., Atomi H., Imanaka T., Extremely stable andversatile carboxylesterase from a hyperthermophilic archaeon. Appl Environ Microbiol., 2002, 68:3925-3931.
    [34] Henke E., Bornscheuer U. T., Schmid R. D., Pleiss J., A molecular mechanism of enantiorecognition of tertiary alcohols by carboxylesterases, Chem. Bio. Chem., 2003, 4:485-493.
    [35] Sehgal A. C., Tompson R., Cavanagh J., Kelly R. M., Structural and catalytic response to temperature and cosolvents of carboxylesterase EST1 from the extremely thermoacidophilic archaeon Sulfolobus solfataricus P1, Biotechnol Bioeng., 2002, 80:784-793.
    [36] Sehgal A. C., Kelly R. M., Enantiomeric resolution of 2-aryl propionic esters with hyperthermophilic and mesophilic esterases: contrasting thermodynamic mechanisms, J. Am. Chem. Soc., 2002, 124:8190-8191.
    [37] Guagliardi A., Cerchia L., Rossi M., An intracellular protease of the crenarchaeon Sulfolobus solfataricus, which has sequence similarity to eukaryotic peptidases of the CD clan, Biochem. J., 2002, 368:357-363.
    [38] Chang L. S., Hicks P. M., Kelly R. M., Protease I from Pyrococcus furiosus, Methods Enzymol., 2001, 330:403-413.
    [39] Catara G., Ruggiero G., La Cara F., Digilio F. A., Capasso A., Rossi M., A novel extracellular subtilisin-like protease from the hyperthermophile Aeropyrum pernix K1: biochemical properties, cloning, and expression, Extremophiles, 2003, 7:391-399.
    [40] Sako Y., Croocker P. C., Ishida Y., An extremely heat-stable extracellular proteinase (aeropyrolysin) from the hyperthermophilic archaeon Aeropyrum pernix K1, FEBS Lett, 1997, 415:329-334.
    [41] Croocker P. C., Sako Y., Uchida A., Purification and characterization of an intracellular heat-stable proteinase (pernilase) from the marine hyperthermophilic archaeon Aeropyrum pernix K1. Extremophiles, 1999, 3:3-9.
    [42] Gao R. J., Feng Y., Ishikawa K., Ishid H., S Ando., Kosugi Y., Cao S. G., Cloning, purification and properties of a hyperthermophilic esterase from archaeon Aeropyrum pernix K1. J. Mol.Catal B: Enzymatic., 2003, 24: 1–8
    [43] Bartlam M., Wang G. G., Gao R. J., Yang H. T., Zhao X. D., Xie G. Q., Cao S. G., Feng Y., and Rao Z. H., Crystal structure of an acylpeptide hydrolase/esterase from Aeropyrum pernix K1, Structure, 2004, 12:1-20
    [44] Cheng T. C., Ramakrishnan V., Chan S. I., Purification and characterization of a cobalt-activated carboxypeptidase from the hyperthermophilic archaeon Pyrococcus furiosus, Protein Sci., 1999, 8:2474-2486.
    [45] Arndt J. W., Hao B., Ramakrishnan V., Cheng T., Chan S. I., Chan M. K., Crystal structure of a novel carboxypeptidase from the hyperthermophilic archaeon Pyrococcus furiosus, Structure (Camb), 2002, 10:215-224.
    [46] Maher M. J., Ghosh M., Grunden A. M., Menon A. L., Adams M. W., Freeman H. C., Guss J. M., Structure of the prolidase from Pyrococcus furiosus, Biochemistry, 2004, 43:2771-2783.
    [47] de Vos W. M., Voorhorst W. G., Dijkgraaf M., Kluskens L. D., Van der Oost J., Siezen R. J., Purification, characterization, and molecular modeling of pyrolysin and other extracellular thermostable serine proteases from hyperthermophilic microorganisms, Methods Enzymol., 2001, 330:383-393.
    [48] Tanaka H., Chinami M., Mizushima T., Ogasahara K., Ota M., Tsukihara T., Yutani K., X-ray crystalline structures of pyrrolidone carboxyl peptidase from a hyperthermophile, Pyrococcus furiosus, and its cys-free mutant. J. Biochem., (Tokyo), 2001, 130:107-118.
    [49] Harwood V. J., Schreier H. J., Prolyl oligopeptidase from Pyrococcus furiosus. Methods Enzymol., 2001, 330:445-454.
    [50] Harris M. N., Madura J. D., Ming L. J., Harwood V. J., Kinetic and mechanistic studies of prolyl oligopeptidase from the hyperthermophile Pyrococcus furiosus, J. Biol. Chem., 2001, 276:19310-19317.
    [51] Meng L., Ruebush S., D'Souza V. M., Copik A. J., Tsunasawa S., Holz R. C., Overexpression and divalent metal binding properties of the methionyl aminopeptidase from Pyrococcus furiosus, Biochemistry, 2002, 41:7199-7208.
    [52] Tahirov T. H., Oki H,. Tsukihara T., Ogasahara K., Yutani K., Ogata K., Izu Y., Tsunasawa S., Kato I., Crystal structure of methionine aminopeptidase from hyperthermophile, Pyrococcus furiosus, J. Mol. Biol., 1998, 284:101-124.
    [53] Sokabe M., Kawamura T., Sakai N., Yao M., Watanabe N.,Tanaka I., The X-ray crystal structure of pyrrolidonecarboxylate peptidase from hyperthermophilic archaea Pyrococcus horikoshii, J. Struct. Funct. Genomics., 2002, 2:145-154.
    [54] Du X., Choi I. G., Kim R., Wang W., Jancarik J., Yokota H., Kim S. H., Crystal structure of an intracellular protease from Pyrococcus horikoshii at 2-? resolution, Proc. Natl. Acad. Sci. USA, 2000, 97:14079-14084.
    [55] Onoe S., Ando S., Ataka M., Ishikawa K., Active site of deblocking aminopeptidase from Pyrococcus horikoshii, Biochem. Biophys. Res. Commun., 2002, 290:994-997.
    [56] Fukui T., Eguchi T., Atomi H., Imanaka T., A membrane-bound archaeal Lon protease displays ATP-independent proteolytic activity towards unfolded proteins and ATP-dependent activity for folded proteins, J. Bacteriol., 2002, 184:3689-3698.
    [57] Kannan Y., Koga Y., Inoue Y., Haruki M., Takagi M., Imanaka T., Morikawa M., Kanaya S., Active subtilisin-like protease from a hyperthermophilic archaeon in a form with a putative prosequence, Appl. Environ. Microbiol., 2001, 67:2445-2452.
    [58] Morikawa M., Imanaka T., Thiol protease from Thermococcus kodakaraensis KOD1, Methods Enzymol., 2001, 330:424-433.
    [59] Singleton M. R., Littlechild J. A., Pyrrolidone carboxylpeptidase from Thermococcus litoralis, Methods Enzymol., 2001, 330:394-403.
    [60] Hicks P. M., Chang L. S., Kelly R. M., Homomultimeric protease and putative bacteriocin homolog from Thermotoga maritime, Methods Enzymol., 2001, 330:455-460.
    [61] Barrett A. J., Rawlings N. D., Evolutionary lines of cysteine peptidases, Biol Chem, 2001, 382:727-733.
    [62] Singleton M., Isupov M., Littlechild J., X-ray structure of pyrrolidone carboxyl peptidase from the hyperthermophilic archaeon Thermococcus litoralis, Struct Fold. Des., 1999, 7:237-244.
    [63] Jaenicke R., and B?hm G., The stability of proteins in extreme environments, Curr. Opin. Struct. Biol., 1998, 8: 738–748.
    [64] Bernhardt G., Ludemann H. D., Jaenicke R., Konig H., Stetter K. O., Biomolecules are unstable under “black smoker” conditions, Natur-wissenschaften, 1984, 71:583-586.
    [65] Jaenicke R., What ultrastable globular proteins teach us about protein stabililty, Biochemistry (Moscow), 1998, 63:312-321.
    [66] Reinhard S., and Wolfgang L., Thermophilic adaptation of proteins, Critical Reviews in Biochemistry and Molecular Miology, 2001, 36:39-106.
    [67] Pace, C. N. and Scholtz, J. M., Measuring the conformational stability of a protein. In: Protein structure-a practical approach, 1997, pp. 299–321. (Creighton, T. E., Ed.). Oxford University Press, Oxford, New York.
    [68] Schmid, F. X., Optical spectroscopy to characterize protein conformation and conformational changes. In: Protein Structure—A Practical Approach, 1997, pp. 261–297. (Creighton, T. E., Ed.). Oxford UniversityPress, Oxford.
    [69] Pfeil, W., Protein Stability and Folding. A Collection of Thermodynamic Data, 1998, pp. 3–14. Springer-Verlag, Berlin.
    [70] Becktel W. J., Schellman J. A., Protein stability curves, Biopolymers, 1987, 26:1859-1877.
    [71] Pace C. N., Measuring and increasing protein stability, Tibtech-april., 1990, 8:93-98.
    [72] Ninad V. P., and Kim A., Heat capacity in proteins, Annu. Rev. Phys. Chem., 2005, 56:521–48.
    [73] Gomez J., Hilser V. J., Xie D., Freire E., The heat capacity of proteins, Proteins, 1995, 22:404-12.
    [74] Zhou H. X., Toward the physical basis of thermophilic proteins: linking of enriched polar interactions and reduced heat capacity of unfolding, Biophysical Journal, 2002, 83:3126-3133.
    [75] Hollien J., and Marqusee S., A thermodynamic comparison of mesophilic and thermophilic ribonucleases H, Biochmeistry, 1999, 38: 3831–3836.
    [76] Deutschman W. A., Dahlquist F. W., Thermodynamic basis for the increased thermostability of CheY from the hyperthermophile Thermotoga maritime, Biochemistr,. 2001, 40:13107–13113.
    [77] Motono C., Oshima T., and Yamagishi A., High thermal stability of 3-isopropylmalate dehydrogenase from Thermus thermophilus resulting from low △△Cp of unfolding, Protein Eng., 2001, 14:961–966.
    [78] Shiraki, K., Nishikori S., Fujiwara S., Mashimoto H., Kai Y., Takagi M., and T Imanaka., Comparative analyses of the conformational stability of a hyperthermophilic protein and its mesophilic counterpart, Eur. J. Biochem. 2001, 268:4144–4150.
    [79] Nojima H., Ikai A., Oshima T., and Noda H., Reversible thermal unfolding of thermostable phosphoglycerate kinase: thermostability associated with mean zero enthalpy change, J. Mol. Biol., 1977, 116:429–442.
    [80] Knapp S., Karshikoff A., Berndt K. D., Christova P., Atanasov B., and Ladenstein R., Thermal unfolding of the DNA-binding protein Sso7d from the hyperthermophile Sulfolobus solfataricus, J. Mol. Biol., 1996, 264:1132–1144.
    [81] Knapp S., Mattson P. T., Christova P., Berndt K. D., Karshikoff A., Vihinen M., Smith C. I. E., and Ladenstein R., Thermal unfolding of small proteins with SH3 domain folding pattern, Proteins, 1998, 31:309–319.
    [82] Filimonov V. V., Azuaga A. I., Viguera A. R., Serrano L., and Mateo P. L., A thermodynamic analysis of a family of small globular proteins: SH3 domains. Biophys. Chem., 1999, 77:195–208.
    [83] Elcock A. H. The stability of salt bridges at high temperatures: implications for hyperthermophilic proteins, J. Mol. Biol., 1998, 284:489–502.
    [84] Szilagyi A., and Zavodszky P., Structural differences between mesophilic, moderately thermophilic and extremely thermophilic protein subunits: results of a comprehensive survey, Structur,. 2000, 8:493–504.
    [85] Loladze V. V., Ermolenko D. N., and Makhatadze G. I., Heat capacity changes upon burial of polar and nonpolar groups in proteins, Protein Sci., 2001, 10:1343–1352.
    [86] Spolar R. S., Livingstone J. R., and Record M. T., Use of liquid hydrocarbon and amide transfer data to estimate contributions to thermodynamic functions of protein folding from the removal of nonpolar and polar surface from water, Biochemistry, 1992, 31:3947–3955.
    [87] Myers J. K., Pace C. N., and Scholtz J. M., Denaturant m values and heat capacity changes: relation to changes in accessible surface areas of protein unfolding, Prot. Sci., 1995, 4:2138–2148.
    [88] Murphy K. P., and Freire E., Thermodynamics of structural stability and cooperative folding behavior in proteins, Adv. Protein Chem., 1992, 43:313–361.
    [89] Hollien J., and Marqusee S., A thermodynamic comparison of mesophilic and thermophilic ribonucleases H, Biochemistry, 1999, 38:3831–3836.
    [90] Ishikawa K., Okumura M., Katayanagi K., Kimura S., Kanaya S., and Morikawa K., Crystal structure of RNase H from Thermus thermophilus HB8 refined at 2.8 ? resolution, J. Mol. Biol., 1993, 230:529-542.
    [91] Katayanagi K., Miyagawa M., Matsushima M., Ishikawa M., Kanaya S., Nakamura H., Ikehara M., Matsuzaki T., Morikawa K., Structural details of ribonuclease H from Escherichia coli as refined to an atomic resolution, J. Mol. Biol., 1992, 223:1029-1052.
    [92] Plaza del Pino I. M., Ibarra-Molero B., and Sanchez-Ruiz J. M. Lower kineticlimit to protein thermal stability: a proposal regarding protein stability in vivo and its relation with misfolding diseases, Proteins, 2000, 40: 58–70.
    [93] Perl D., Welker C., Schindler T., Schr?der K., Marahiel M. A., Jaenicke R., and Schmid F. X., Conservation of rapid two-state folding in mesophilic, thermophilic and hyperthermophilic cold shock proteins, Nat. Struct. Biol., 1998, 5:229–235.
    [94] Dams T., and Jaenicke R., Stability and folding of dihydrofolate reductase from the hyperthermophilic bacterium Thermotoga maritime, Biochemistry, 1999, 38: 9169–9178.
    [95] Haney P. J., Badger J. H., Buldak G. L., Reich C. I., Woese C. R., and Olsen G. J., Thermal adaptation analyzed by comparison of protein sequences from mesophilic and extremely thermophilic Methanococcus species, Proc. Natl. Acad. Sci. US , 1999, 96:3578–3583.
    [96] Cambillau C., and Claverie J. M., Structural and genomic correlates of hyperthermostability, J. Biol. Chem., 2000, 275:32383–32386.
    [97] Chakravarty S., and Varadarajan R., Elucidation of determinants of protein stability through genome sequence analysis, FEBS Lett., 2000, 470: 65–69.
    [98] Thompson M. J., and Eisenberg D., Transproteomic evidence of a loop-deletion mechanism for enhancing protein thermostability, J. Mol. Biol., 1999, 290:595–604.
    [99] Matsumura M., Signor G., and Matthews B. W., Substantial increase of protein stability by multiple disulphide bonds, Nature, 1989, 342:291–293.
    [100] Volkin D. B., Klibanov A. M., Thermal destruction processes in proteins involving cystine residues, J. Biol. Chem., 1987, 262:2945–2950.
    [101] Vieille C., and Zeikus G. J., Hyperthermophilic enzymes: sources, uses and molecular mechanisms for thermostability, Microbiology and molecular biology reviews, 2001, 65:1-43.
    [102] Kellis J. T., Nyberg K., Sali D., Fersht A. R., Contribution of hydrophobic interactions to protein stability, Nature, 1988, 333:784-786.
    [103] Haney P. J., Stees M., and Konisky J., Analysis of thermal stabilizing interactions in mesophilic and thermophilic adenylate kinases from the genus Methanococcus, J. Biol. Chem., 1999, 274:28453–28458.
    [104] Klein A. R., Breitung J., Linder D., Stetter K. O., and Thauer R. K., N5, N10-methenyltetrahydromethanopterin cyclohydrolase from the extremely thermophilic sulfate reducing Archaeoglobus fulgidus: comparison of its properties with those of the cyclohydrolase from the extremely thermophilic Methanopyrus kandleri, Arch. Microbiol., 1993, 159:213–219.
    [105] Makhatadze G. I. and Privalov P. L. Energetics of protein structure, Adv. Protein Chem., 1995, 47: 307–425.
    [106] Burley S. K., and Petsko G. A., Aromatic-aromatic interaction: a mechanism of protein structure stabilization, Science, 1985, 229:23–28.
    [107] Teplyakov A. V., Kuranova I. P., Harutyunyan E. H., Vainshtein B. K., Frommel C., Hohne W. E., and Wilson K. S., Crystal structure of thermitase at 1.4? resolution, J. Mol. Biol., 1990, 214: 261–279
    [108] Kannan R., Vishveshwara S., Aromatic clusters: a determinant of thermal stability of thermophilic proteins, Protein engineering, 2000, 13:753-761.
    [109] Dougherty D. A., Cation-π interactions in chemistry and biology: a new view of benzene, Phe, Tyr, and Trp, Science,1996, 271:163–168.
    [110] Shirley, B. A., Stanssens P., Hahn U., and Pace C. N., Contribution of hydrogen bonding to the conformational stability of ribonuclease T1, Biochemistry, 1992, 31:725–732.
    [111] Tanner J. J., Hecht R. M., Krause K. L., Determinants of enzyme thermostability observed in the molecular structure of Thermus aquaticus D-glyceraldehyde -3-phosphate dehydrogenase at 2.5 ? resolution, Biochemistry, 1996, 35: 2597–2609.
    [112] Ribeiro S. M., Darimont B., Sterner R., Huber R., Small structural changes account for the high thermostability of 1[4Fe-4S] ferredoxin from the hyper thermophilic bacterium Thermotoga maritime, Structure, 1996, 4:1290–1301.
    [113] Dill K. A., Dominant forces in protein folding, Biochemistry, 1990, 29:7133–7155.
    [114] Anderson D. E., Becktel W. J., Dahlquist F. W., pH-induced denaturation of proteins: a single salt bridge contributes 3–5 kcal/mol to the free energy of folding of T4 lysozymem, Biochemistry, 1990, 29:2403–2408.
    [115] Yip K. S., Stillman T. J., Britton K. L., Artymiuk P. J., Baker P. J., Sedelnikova S. E., Engel P. C., Pasquo A., Chiaraluce R., Consalvi V., Scandurra R., Rice D. W.. The structure of Pyrococcus furiosus glutamate dehydrogenase reveals a key role for ion-pair networks in maintaining enzyme stability at extreme temperatures, Structure, 1995, 3:1147–1158.
    [116] Kumar S., and Nussinov R., Salt bridge stability in monomeric proteins, J. Mol. Biol, 1999, 293:1241–1255.
    [117] Ogasahara K., Lapshina E. A., Sakai M., Izu Y., Tsunasawa S., Kato I., and Yutani K., Electrostatic stabilization in methionine aminopeptidase from hyperthermophile Pyrococcus furiosus, Biochemistry, 1998, 37:5939–5946.
    [118] Tomschy A., Bohm G., Jaenicke R., The effect of ion pairs on the thermal stability of D-glyceraldehyde 3-phosphate dehydrogenase from the hyperthermophilic bacterium Thermotoga maritime, Protein Eng., 1994, 7:1471–1478.
    [119] Donna L. L., Christopher D. S., Jo-Jin L., Zachary S. H., Bruce T., and Daniel P. R., Surface salt bridges, double-mutant cycles, and protein stability: an experimental and computational analysis of the interaction of the Asp 23 side chain with the N-terminus of the N-terminal domain of the ribosomal protein L9, Biochemistry, 2003, 42: 7050-7060.
    [120] George I. M., Vakhtang V. L., Dmitri N. E., Chen X. F., Thomas S. T., Contribution of surface salt bridges to protein stability: guidelines for protein engineering, J. Mol. Biol., 2003, 327:1135-1148.
    [121] Kumar S., Tsai C. J., and Nussinov R., Factors enhancing protein thermostability, Prot. Eng., 2000, 13:179-191.
    [122] Facchiano A. M., Colonna G., and Ragone R., Helix stabilizing factors and stabilization of thermophilic proteins: an X-ray based study, Prot. Eng., 1998, 11:753-760.
    [123] Auerbach G., Huber R., Grattinger M., Zaiss K., Schurig H., Jaenicke R., and Jacob U., Closed structure of phosphoglycerate kinase from Thermotoga maritima reveals the catalytic mechanism and determinants of thermal stability, Structure, 1997, 5:1475–1483.
    [124] Nicholson H., Becktel W. J., and Matthews B. W., Enhanced protein thermostability from designed mutations that interact with a-helix dipoles, Nature, 1988, 336:651–656.
    [125] Lim J. H., Yu Y. G., Han Y. S., Cho S., Ahn B. Y., Kim S. H., and Cho Y., The crystal structure of an Fe-superoxide dismutase from the hyperthermophile Aquifex pyrophilus at 1.9? resolution: structural basis for thermostability, J. Mol. Biol., 1997, 270:259–274.
    [126] Vetriani C., Maeder D. L., Tolliday N., Yip K. S., Stillman T. J., Britton K. L., Rice D. W., Klump H. H., and Robb F. T., Protein thermostability above 100°C: a key role for ionic interactions, Proc. Natl. Acad. Sci. USA, 1998, 95:12300–12305.
    [127] Rahman R.N.Z.A., Fujiwara S., Nakamura H., Takagi M., and Imanaka T., Ion pairs involved in maintaining a thermostable structure of glutamate dehydrogenase from a hyperthermophilic archaeon, Biochem. Biophys. Res. Commun. 1998, 248:920–926.
    [128] Lebbink J. H. G., Knapp S., van der Oost J., Rice D., Ladenstein R., and de Vos W. M., Engineering activity and stability of Thermotoga maritime glutamate dehydrogenase II: construction of a 16-residue ion-pair network at the subunit interface, J. Mol. Biol., 1999, 289:357–369.
    [129] Moriyama H., Onodera K., Sakurai M., Tanaka N., Kirino-Kagawa H., Oshima T., and Katsube Y., The crystal structures of mutated 3-isopropylmalate dehydrogenase from Thermus thermophilus HB8 and their relationship to the thermostability of the enzyme, J. Biochem., 1995, 117:408–413.
    [130] Thoma R., Hennig M., Sterner R., and Kirschner K., Structure and function of mutationally generated monomers of dimeric phosphoribosyl-anthranilate isomerase from Thermotoga maritime, Structure, 2000, 8:265-276.
    [131] Kimura S., Kanaya S., and Nakamura H., Thermostabilization of Escherichia coli ribonuclease HI by replacing left-handed helical Lys95 with Gly or Asn, J. Biol. Chem., 1992, 267:22014–22017.
    [132] Sanz-Aparicio J., Hermoso J. A., Ripoll M. M., Gonzalez B., Lopez C. C., and Polaina J. Structural basis of increased resistance to thermal denaturation induced by single amino acid substitution in the sequence of b-glucosidase A from Bacillus polymyxa, Proteins Struct. Funct. Gene, 1998, 33:567–576.
    [133] Caflisch A., and Karplus M., Acid and thermal denaturation of barnase investigated by molecular dynamics simulations, J. Mol. Biol., 1995, 252:672–708.
    [134] Creveld L. D., Amadei A., van Schaik R. C., Pepermans H. A., de Vlieg J., and Berendsen H. J., Identification of functional and unfolding motions of cutinase as obtained from molecular dynamics computer simulations, Proteins, 1998, 33:253–264.
    [135] Pedone E., Cannio R., Saviano M., Bartolucci S., Prediction and experimental testing of Bacillus acidocaldarius thioredoxin stability, Biochem. J., 1999, 339:309-317.
    [136] Gao D., Zhan C. G., Modeling evolution of hydrogen bonding and stabilization of transition states in the process of cocaine hydrolysis catalyzed by human butyrylcholinesterase, Proteins: Structure, Function, and Bioinformatics, 2006, 62:99–110.
    [137] Lazaridis T., Lee I., and Karplus M., Dynamics and unfolding pathways of a hyperthermophilic and a mesophilic rubredoxin, Protein Sci., 1997, 6:2589–2605.
    [138] Pikkemaat M., Linssen A. B. M., Berendsen H. J. C., Janssen D. B. J., Molecular dynamics simulations as a tool for improving protein stability, Protein engineering, 2002, 15:185-192.
    [139] Mansfeld J., Vriend G., Dijkstra B. W., Veltman O. R., Van den Burg B., Venema G., Ulbrich-Hofmann R., Eijsink V. G. H., Extreme stabilization of a thermolysin-like protease by an engineered disulfide bond, J. Biol. Chem., 1997, 272:11152–11156.
    [140] Marshall S. A., Morgan C. S., Mayo S. L., Electrostatics significantly affect the stability of designed homeodomain variants, J. Mol. Biol., 2002, 316, 189–199.
    [141] Schwehm J. M., Fitch C. A., Dang B. N., Garcia-Moreno B., Stites W. E., Changes in stability upon charge reversal and neutralization substitution in staphylococcal nuclease are dominated by favourable electrostatic effects, Biochemistry, 2003, 42:1118–1128.
    [142] Puchkaev A. V., Koo L. S., Ortiz de Montellano P. R., Aromatic stacking as a determinant of the thermal stability of CYP119 from Sulfolobus solfataricus, Arch. Biochem. Biophys., 2003, 409:52–58.
    [143] Vincent G. H., Alexandra B., Sigrid G., Reidun S., Bj?rnar S., Rational engineering of enzyme stability, Journal of Biotechnology, 2004, 113:105-120.
    [144] Vincent G. H., Sigrid G., Torben V. B., Burg B., Directed evolution of enzyme stability, Biomolecular Engineering, 2005, 22:21-30.
    [145] Stemmer W. P. C., Rapid evolution of a protein in vitro by DNA shuffling, Nature, 1994, 370:389-391.
    [146] Chen K, and Arnold F. H., Tuning the activity of an enzyme for unusual environments: sequential random mutagenesis of subtilisin E for catalysis in dimethylformamide, Proc. Natl. Acad. Sci. USA, 1993, 90:5618-5622.
    [147] Lutz S., and Patrick W. M., Novel methods for directed evolution of enzymes: quality, not quantity, Current Opinion in Biotechnology, 2004, 15:291–297
    [148] Ness J. E., Welch M., Giver L., DNA shuffling of subgenomic sequences of subtilisin, Nat. Biotech., 1999, 17:893-896.
    [149] Martin A., Kather I., Schmid F. X., Origins of the high stability of an in vitro-selected cold-shock protein, J. Mol. Biol., 2002, 318:863-875.
    [150] Martin A., Sieber V., Schmid F. X., In-vitro selection of highly stabilized protein variants with optimized surface, J. Mol. Biol., 2001, 309:717-726.
    [151] Mallela M. G. Krishna and Englander S. W., The N-terminal to C-terminal motif in protein folding and function, Proc. Natl. Acad. Sci. USA, 2005, 102:1053-1058.
    [152] Pfuhl M., Improta S., Politou A. S., and Pastore A., When a module is also a domain: the roxle of the N terminus in the stability and the dynamics of immunoglobulin domains from titin, J. Mol. Biol., 1997, 265:242–256.
    [153] Mandrich L., Merone L., Pezzullo M., Cipolla L., Nicotra F., Role of the N terminus in enzyme activity, stability and specificity in thermophilic esterases belonging to the HSL family, J. Mol. Biol., 2005, 345:501–512.
    [154] Leung K. W., Liaw Y. C., Chan S. C., Lo H. Y., Musayev F. N., Chen J. Z. W., Fang H. J., and Chen H. M., Significance of local electrostatic interactions in staphylococcal nuclease studied by site-directed mutagenesis, J. Biol. Chem., 2001, 276:46039–46045.
    [155] Bau R., Rees D. C., Kurtz D. M., Scott R. A., Huang H., Adams M. W. W., Eidsness M. K., Crystal structure of rubredoxin from Pyrococcus furiosus at 0.95 ? resolution, and the structures of N-terminal methionine and formylmethionine variants of Pf Rd. Contributions of N-terminal interactions to thermostability, J. Biol. Inorg. Chem., 1998, 3:484–493.
    [156] Fulop V., Bocskei Z., and Polgar L., Prolyl oligopeptidase: an unusual β-propeller domain regulates proteolysis, Cell, 94, 161-170.

© 2004-2018 中国地质图书馆版权所有 京ICP备05064691号 京公网安备11010802017129号

地址:北京市海淀区学院路29号 邮编:100083

电话:办公室:(+86 10)66554848;文献借阅、咨询服务、科技查新:66554700