Sites of cytochrome b‐563 reduction, and the mode of action of DNP‐INT and DBMIB in the chloroplast cytochrome b‐563/f complex

FEBS Letters

O'Keefe, Daniel P.¹ 

[1] Biochemicals Department, Experimental Station, E.I. du Pont de Nemours and Co., Inc., Wilmington, DW 19898, USA

关键词: Chloroplast;    Cytochrome b;    Electron transfer;    Ferredoxin;    Plastoquinone;    DBMIB;    2;    5-dibromo-3-methyl-6-isopropyl-p-benzoquinone;    DNP-INT;    2-iodo-6-isopropyl-3-methyl-2′;    4;    4′-trinitrodiphenyl ether;   

DOI  :  10.1016/0014-5793(83)80786-8

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

When ferredoxin is the reductant of cytochrome b-563 in the chloroplast cytochrome b-563/f complex, the reaction rate varies with pH in a manner which permits identification of a plastoquinone/plastosemiquinone couple as an intermediate in the reaction. The requirement for the inhibitor, DNP-INT, in this reaction, suggests that there are two sites in the complex where plastosemiquinone can react with cytochrome(s) b-563. The ineffectiveness of DBMIB in promotion of ferredoxin-mediated cytochrome b-563 reduction has led to a model where DBMIB and DNP-INT inhibit different electron transfer steps at the same, or overlapping, sites in the complex.

【 授权许可】

Unknown