Secondary structure and thermal stability of the extrinsic 23 kDa protein of photosystem II studied by Fourier transform infrared spectroscopy

被引:18
|
作者
Zhang, HM
Ishikawa, Y
Yamamoto, Y
Carpentier, R
机构
[1] Univ Quebec, Grp Rech Energie & Informat Biomol, Trois Rivieres, PQ G9A 5H7, Canada
[2] Okayama Univ, Fac Sci, Dept Biol, Okayama 700, Japan
关键词
extrinsic protein; Fourier transform infrared; oxygen evolving complex 23; photosystem II; secondary structure;
D O I
10.1016/S0014-5793(98)00371-8
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
The secondary structure and thermal stability of the extrinsic 23 kDa protein (OEC23) of spinach photosystem II have been characterized in solution between 25 and 75 degrees C using Fourier transform infrared spectroscopy. Quantitative analysis of the amide I band (1700-1600 cm(-1)) shows that OEC23 contains 5% alpha-helix, 37% beta-sheet, 24% turn, and 34% disorder structures at 25 degrees C. No appreciable conformational changes occur below 45 degrees C. At elevated temperatures, the beta-sheet structure is unfolded into the disorder structure with a major conformational transition occurring at 55 degrees C. Implications of these results for the functions of OEC23 in photosystem II are discussed. (C) 1998 Federation of European Biochemical Societies.
引用
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页码:347 / 351
页数:5
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