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Title: Electron transport pathways in spinach chloroplasts. Reduction of the primary acceptor of photosystem II by reduced nicotinamide adenine dinucleotide phosphate in the dark

Abstract

Addition of NADPH to osmotically lysed spinach chloroplasts results in a reduction of the primary acceptor (Q) of Photosystem II. This reduction of Q reaches a maximum of 50% in chloroplasts maintained under weak illumination and requires added ferredoxin and Mg/sup 2 +/. The reaction is inhibited by (i) an antibody to ferredoxin-NADP/sup +/ reductase (EC 1.6.7.1), (ii) treatment of chloroplasts with N-ethylmaleimide in the presence of NADPH, (iii) disulfodisalicylidenepropanediamine, (iv) antimycin, and (v) acceptors of non-cyclic electron transport. Uncouplers of phosphorylation do not affect NADPH-driven reduction of Q. It is proposed that electron flow from NADPH to Q may occur in the dark by a pathway utilising portions of the normal cyclic and non-cyclic electron carrier sequences. The possible in vivo role for such a pathway in redox poising of cyclic electron transport and hence in controlling the ATP/NADPH supply ratio is discussed.

Authors:
; ; ; ;
Publication Date:
Research Org.:
Brookhaven Natl. Lab., Upton, NY
OSTI Identifier:
5063502
Resource Type:
Journal Article
Journal Name:
Biochim. Biophys. Acta; (United States)
Additional Journal Information:
Journal Volume: 547
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES; CHLOROPLASTS; ELECTRON TRANSFER; BIOLOGICAL PATHWAYS; CYTOCHROMES; EXPERIMENTAL DATA; FERREDOXIN; FLUORESCENCE; INHIBITION; MAGNESIUM; NADP; NEM; OXIDOREDUCTASES; PHOSPHORYLATION; PHOTOCHEMICAL REACTIONS; REDOX REACTIONS; SPINACH; ALKALINE EARTH METALS; CELL CONSTITUENTS; CHEMICAL REACTIONS; COENZYMES; DATA; DRUGS; ELEMENTS; ENZYMES; FOOD; IMIDES; INFORMATION; LUMINESCENCE; METALS; NUCLEOTIDES; NUMERICAL DATA; ORGANIC COMPOUNDS; ORGANIC NITROGEN COMPOUNDS; PIGMENTS; PROTEINS; RADIOSENSITIZERS; RESPONSE MODIFYING FACTORS; VEGETABLES; 500200* - Environment, Atmospheric- Chemicals Monitoring & Transport- (-1989)

Citation Formats

Mills, J D, Crowther, D, Slovacek, R E, Hind, G, and McCarty, R E. Electron transport pathways in spinach chloroplasts. Reduction of the primary acceptor of photosystem II by reduced nicotinamide adenine dinucleotide phosphate in the dark. United States: N. p., 1979. Web. doi:10.1016/0005-2728(79)90101-4.
Mills, J D, Crowther, D, Slovacek, R E, Hind, G, & McCarty, R E. Electron transport pathways in spinach chloroplasts. Reduction of the primary acceptor of photosystem II by reduced nicotinamide adenine dinucleotide phosphate in the dark. United States. https://doi.org/10.1016/0005-2728(79)90101-4
Mills, J D, Crowther, D, Slovacek, R E, Hind, G, and McCarty, R E. 1979. "Electron transport pathways in spinach chloroplasts. Reduction of the primary acceptor of photosystem II by reduced nicotinamide adenine dinucleotide phosphate in the dark". United States. https://doi.org/10.1016/0005-2728(79)90101-4.
@article{osti_5063502,
title = {Electron transport pathways in spinach chloroplasts. Reduction of the primary acceptor of photosystem II by reduced nicotinamide adenine dinucleotide phosphate in the dark},
author = {Mills, J D and Crowther, D and Slovacek, R E and Hind, G and McCarty, R E},
abstractNote = {Addition of NADPH to osmotically lysed spinach chloroplasts results in a reduction of the primary acceptor (Q) of Photosystem II. This reduction of Q reaches a maximum of 50% in chloroplasts maintained under weak illumination and requires added ferredoxin and Mg/sup 2 +/. The reaction is inhibited by (i) an antibody to ferredoxin-NADP/sup +/ reductase (EC 1.6.7.1), (ii) treatment of chloroplasts with N-ethylmaleimide in the presence of NADPH, (iii) disulfodisalicylidenepropanediamine, (iv) antimycin, and (v) acceptors of non-cyclic electron transport. Uncouplers of phosphorylation do not affect NADPH-driven reduction of Q. It is proposed that electron flow from NADPH to Q may occur in the dark by a pathway utilising portions of the normal cyclic and non-cyclic electron carrier sequences. The possible in vivo role for such a pathway in redox poising of cyclic electron transport and hence in controlling the ATP/NADPH supply ratio is discussed.},
doi = {10.1016/0005-2728(79)90101-4},
url = {https://www.osti.gov/biblio/5063502}, journal = {Biochim. Biophys. Acta; (United States)},
number = ,
volume = 547,
place = {United States},
year = {Mon Jan 01 00:00:00 EST 1979},
month = {Mon Jan 01 00:00:00 EST 1979}
}