pH‐dependent reversible inhibition of violaxanthin de‐epoxidase by pepstatin related to protonation‐induced structural change of the enzyme

FEBS Letters

Kuwabara, Tomohiko²  Kawano, Mitsuko¹ 

[1]Master's Program in Biosystem Studies, University of Tsukuba, Tsukuba 305-8572, Japan

[2]Institute of Biological Science, University of Tsukuba, Tsukuba 305-8572, Japan

关键词: Pepstatin;    Photoprotection;    Protonation-induced conformational change;    Violaxanthin de-epoxidase;    Xanthophyll cycle;    DMSO;    dimethyl sulfoxide;    MGDG;    monogalactosyldiacylglycerol;    VDE;    violaxanthin de-epoxidase;   

DOI  :  10.1016/S0014-5793(00)01991-8

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The redox enzyme violaxanthin de-epoxidase (VDE) was found to be sensitive to pepstatin, a specific inhibitor of aspartic protease. The inhibition was similar to that of aspartic protease in that it was reversible and accompanied by the protonation of the enzyme. Of the two peaks of VDE appearing on anion exchange chromatography, VDE-I predominated at pH 7.2. On lowering the pH of the chromatography, VDE-I decreased and VDE-II increased. Furthermore, re-chromatography of either peak yielded both peaks. These results suggest that VDE-I and VDE-II are interconvertible depending on pH, and thus, they represent the de-protonated and protonated forms of the enzyme, respectively. Presumably the protonation-induced structural change of the enzyme is responsible for the interaction with pepstatin, and also with substrate.

【 授权许可】

Unknown