Advanced Search
Syntax
Search...
Volcani treasures
About
Terms of use
Manage
Community:
אסיף מאגר המחקר החקלאי
Powered by ClearMash Solutions Ltd -
Electron uptake and delivery sites on plastocyanin in its reactions with the photosynthetic electron transport system
Year:
1982
Source of publication :
Biochemistry (source )
Authors :
Shahak, Yosepha
;
.
Volume :
21
Co-Authors:
Farver, O., Departments of Chemical Immunology and Biochemistry, Weizmann Institute of Science, Rehovot 76100, Israel
Shahak, Y., Departments of Chemical Immunology and Biochemistry, Weizmann Institute of Science, Rehovot 76100, Israel
Pecht, I., Departments of Chemical Immunology and Biochemistry, Weizmann Institute of Science, Rehovot 76100, Israel
Facilitators :
From page:
1885
To page:
1890
(
Total pages:
6
)
Abstract:
French bean plastocyanin is stoichiometrically and specifically labeled upon reduction by Cr(II)aq ions, yielding a substitution-inert Cr(III) adduct at the protein surface. The effect of the modification on the activity of plastocyanin in electron transfer between photosystems II and I has been investigated. The photoreduction and photooxidation by chloroplasts or by photosystem I reaction centers, respectively, of native and Cr(III)-labeled plastocyanin have been compared. It was found that whereas the photoreduction rates of native and Cr-labeled plastocyanin were indistinguishable, the rates of photooxidation of the modified protein were markedly attenuated relative to those of the native one. This difference in reactivity clearly reflects the perturbation of the electron transfer pathway to P700. These findings, in conjunction with the structure of plastocyanin and the locus of Cr(III) binding on its surface, lead to the following interpretation: (a) There are most probably two physiologically significant, electron transfer sites on plastocyanin. (b) The site involved in the electron transfer to P700 is most likely in the region of tyrosine-83 and the negatively charged patch proximal to it. By elimination we assume that the second site is centered at the hydrophobic region of histidine-87. © 1982 American Chemical Society.
Note:
Related Files :
article
chloroplast
Chloroplasts
metabolism
photosynthesis
Plant Proteins
plastocyanin
Support, Non-U.S. Gov't
Show More
Related Content
More details
DOI :
Article number:
Affiliations:
Database:
Scopus
Publication Type:
article
;
.
Language:
English
Editors' remarks:
ID:
29449
Last updated date:
02/03/2022 17:27
Creation date:
17/04/2018 00:47
Scientific Publication
Electron uptake and delivery sites on plastocyanin in its reactions with the photosynthetic electron transport system
21
Farver, O., Departments of Chemical Immunology and Biochemistry, Weizmann Institute of Science, Rehovot 76100, Israel
Shahak, Y., Departments of Chemical Immunology and Biochemistry, Weizmann Institute of Science, Rehovot 76100, Israel
Pecht, I., Departments of Chemical Immunology and Biochemistry, Weizmann Institute of Science, Rehovot 76100, Israel
Electron uptake and delivery sites on plastocyanin in its reactions with the photosynthetic electron transport system
French bean plastocyanin is stoichiometrically and specifically labeled upon reduction by Cr(II)aq ions, yielding a substitution-inert Cr(III) adduct at the protein surface. The effect of the modification on the activity of plastocyanin in electron transfer between photosystems II and I has been investigated. The photoreduction and photooxidation by chloroplasts or by photosystem I reaction centers, respectively, of native and Cr(III)-labeled plastocyanin have been compared. It was found that whereas the photoreduction rates of native and Cr-labeled plastocyanin were indistinguishable, the rates of photooxidation of the modified protein were markedly attenuated relative to those of the native one. This difference in reactivity clearly reflects the perturbation of the electron transfer pathway to P700. These findings, in conjunction with the structure of plastocyanin and the locus of Cr(III) binding on its surface, lead to the following interpretation: (a) There are most probably two physiologically significant, electron transfer sites on plastocyanin. (b) The site involved in the electron transfer to P700 is most likely in the region of tyrosine-83 and the negatively charged patch proximal to it. By elimination we assume that the second site is centered at the hydrophobic region of histidine-87. © 1982 American Chemical Society.
Scientific Publication
You may also be interested in