Heat-Induced Secondary Structure and Conformation Change of Bovine Serum Albumin Investigated by Fourier Transform Infrared Spectroscopy
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- 作者：Koichi Murayama and Mihoko Tomida
- 刊名：Biochemistry
- 出版年：2004
- 出版时间：September 14, 2004
- 年：2004
- 卷：43
- 期：36
- 页码：11526 - 11532
- 全文大小：118K
- 年卷期：v.43,no.36(September 14, 2004)
- ISSN：1520-4995
文摘
Fourier transform infrared (FT-IR) spectra were measured for an aqueous solution (pD =5.40) of defatted monomer bovine serum albumin (BSA) over a temperature range of 25-90 
C toinvestigate temperature-induced secondary structure and conformation changes. The curve fitting methodcombined with the Fourier self-deconvolution technique allowed us to explore details of the secondarystructure and conformation changes in defatted BSA. Particularly striking in the FT-IR spectra was anobservation of the formation of an irreversible intermolecular 
-sheet of BSA on heating above 70 C. Aband at 1630 cm-1 in the spectra was assigned to short-segment chains connecting 
-helical segments.The transition temperature for the short-segment chains connecting -helical segments is lower by 17-18 C, when compared to those of the -helix, turn, and intermolecular -sheet structures of BSA,suggesting that the -helix and turn structures of BSA are cooperatively denatured on heating. Moreover,the results give an important feature in heat-induced denaturation of BSA that the conformation changesoccur twice around both 57 and 75 C. The appearance of two peaks is interpreted by the collapse of theN-terminal BSA domain due to the crevice in the vicinity between domains I and II at low-temperaturetransition and by the change in cooperative unit composed of the other two BSA domains athigh-temperature transition.
C toinvestigate temperature-induced secondary structure and conformation changes. The curve fitting methodcombined with the Fourier self-deconvolution technique allowed us to explore details of the secondarystructure and conformation changes in defatted BSA. Particularly striking in the FT-IR spectra was anobservation of the formation of an irreversible intermolecular -sheet of BSA on heating above 70 C. Aband at 1630 cm-1 in the spectra was assigned to short-segment chains connecting -helical segments.The transition temperature for the short-segment chains connecting -helical segments is lower by 17-18 C, when compared to those of the -helix, turn, and intermolecular -sheet structures of BSA,suggesting that the -helix and turn structures of BSA are cooperatively denatured on heating. Moreover,the results give an important feature in heat-induced denaturation of BSA that the conformation changesoccur twice around both 57 and 75 C. The appearance of two peaks is interpreted by the collapse of theN-terminal BSA domain due to the crevice in the vicinity between domains I and II at low-temperaturetransition and by the change in cooperative unit composed of the other two BSA domains athigh-temperature transition.