期刊
BIOPHYSICAL CHEMISTRY
卷 104, 期 1, 页码 209-216出版社
ELSEVIER SCIENCE BV
DOI: 10.1016/S0301-4622(02)00368-X
关键词
chloride binding; chloride pump; archaeal rhodopsin; mutation
Pharaonis halorhodopsin (phR) is an inward light-driven chloride ion pump from Natronobacterium pharaonis. In order to clarify the role of Ser-130(phR) residue which corresponds to Ser-115(shR) for salinarum hR on the anion-binding affinity, the wild-type and Ser-130 mutants substituted with Thr, Cys and Ala were expressed in E. coli cells and solubilized with 0.1% n-dodecyl beta-D-maltopyranoside The absorption maximum (lambda(max)) of the S130T mutant indicated a blue shift from that of the wild type in the absence and presence of chloride. For S130A, a large red shift (12 nm) in the absence of chloride was observed. The wild-type and all mutants showed the blue-shift Of A a upon Cl- addition, from which the dissociation constants of Cl- were determined. The dissociation constants were 5, 89, 153 and 159 mM for the wild-type, S130A, S130T and S130C, respectively, at pH 7.0 and 25 degreesC. Circular dichroic spectra of the wild-type and the Ser-130 mutants exhibited an oligomerization. The present study revealed that the Ser-130 of N. pharaonis halorbodopsin is important for the chloride binding. (C) 2003 Elsevier Science B.V. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据