FEBS Letters | |
Two distinct types of ɛ‐binding site exist in chloroplast coupling factor (CF1) | |
Harris, D.A.1  Andralojc, P.J.1  | |
[1] Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, England | |
关键词: Chloroplast; ATP synthase; F1-ATPase; ATPase inhibitor protein; Subunit interaction; CF1; chloroplast coupling factor 1; F1; coupling factor 1; DTT; DL-dithiothreitol; IBZ; o-iodosobenzoate; TEA; triethanolamine; tricine N-tris(hydroxymethyl)-methylglycine; Tris; tris(hydroxymethyl)aminomethane; SDS-PAGE; SDS-polyacrylamide gel electrophoresis; | |
DOI : 10.1016/0014-5793(88)80471-X | |
学科分类:生物化学/生物物理 | |
来源: John Wiley & Sons Ltd. | |
【 摘 要 】
Isolated chloroplast coupling factor (CF1), when depleted of its ɛ-subunit, has a high ATPase activity which can be inhibited by binding ɛ to a single high-affinity (K d = 1.4 × 10−10 M) site. In CF1 reduced by dithiothreitol (DTT), however, ɛ at this binding site is no longer inhibitory. Instead, 3 equivalent, lower affinity (K d = 6 × 10−8 M), inhibitory binding sites for ɛ are observed, whether or not the high-affinity site contains a bound ɛ-subunit. Binding of ɛ to the high-affinity site protects CF1 against trypsin activation, while binding to the low-affinity site does not, showing that occupation of each class of site has a different effect on CF1 structure. The effects of DTT can be interpreted in terms of a reduction in intersubunit cooperativity in CF1.
【 授权许可】
Unknown
【 预 览 】
Files | Size | Format | View |
---|---|---|---|
RO201912020290715ZK.pdf | 582KB | download |