Low pH-induced conformational changes in 33 kD protein of photosystem II

	Low pH-induced conformational changes in 33 kD protein of photosystem II
	Weng, J; Tan, CY; Yu, Y; Ruan, KC; Xu, CH
刊名	CHINESE SCIENCE BULLETIN
	2004
卷号	49 期号:9 页码:921-925
关键词	NBS modification 33 kD protein tryptophan functional conformation
通讯作者	Xu, CH (reprint author), Chinese Acad Sci, Inst Plant Physiol, Shanghai Inst Biol Sci, Shanghai 200032, Peoples R China.,xch@iris.sipp.ac.cn
英文摘要	33 kD protein, located on the lumen side of thylakoid membranes, is one of three extrinsic proteins of Photosystem II (PS H). Previous study showed that NBS modification of W241, the only tryptophan in 33 kD protein, is helpful for understanding the function of W241 in maintaining functional conformation of 33 kD protein. In this paper, studies of both circular dichroism and fluorescence spectra showed that upon decreasing pH from 6.2 to 2.5, the conformation of soluble 33 kD protein changed significantly, with an increase or a decrease in percentage of random coil or (x-helix and turns. The changes in secondary structures of this protein are pH reversible. After NBS modification at pH 2.5, the conformational change of 33 kD protein was kept fixed. The CD ellipticity at 200 nm for NBS-modified 33 kD protein is much lower than that for control, indicating that the unfolding degree of 33 kD protein was enhanced after the NBS modification. Moreover, the conformational flexibility is lost in NBS-modified 33 kD protein, and the conformational change becomes pH irreversible, indicating that NBS modification blocked the reversibility of conformational change of 33 kD protein. The specific binding capability of NBS-modified 33 kD protein is much lower than that of low pH-treated control. Furthermore, the rebinding of modified protein on PS H membranes cannot restore the activity of oxygen evolution. We suggest that it is low pH but not NBS modification of W241 that leads to the conformational change of 33 kD protein from one functional to another non-functional state. The significant capability of proton transport of 33 kD protein is discussed.
学科主题	Science & Technology - Other Topics
类目[WOS]	Multidisciplinary Sciences
关键词[WOS]	MANGANESE-STABILIZING PROTEIN ; EXTRINSIC PROTEIN ; CRYSTAL-STRUCTURE ; OXYGEN-EVOLUTION ; 33-KDA PROTEIN ; TERMINUS ; BINDING ; POLYPEPTIDE ; RESOLUTION
收录类别	SCI
语种	英语
WOS记录号	WOS:000222902200014
内容类型	期刊论文
版本	出版稿
源URL	[http://202.127.25.143/handle/331003/2129]
专题	上海生化细胞研究所_上海生科院生化细胞研究所
推荐引用方式 GB/T 7714	Weng, J,Tan, CY,Yu, Y,et al. Low pH-induced conformational changes in 33 kD protein of photosystem II[J]. CHINESE SCIENCE BULLETIN,2004,49(9):921-925.
APA	Weng, J,Tan, CY,Yu, Y,Ruan, KC,&Xu, CH.(2004).Low pH-induced conformational changes in 33 kD protein of photosystem II.CHINESE SCIENCE BULLETIN,49(9),921-925.
MLA	Weng, J,et al."Low pH-induced conformational changes in 33 kD protein of photosystem II".CHINESE SCIENCE BULLETIN 49.9(2004):921-925.