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Biochemical Properties and Inhibition Kinetics of Phosphatase from Wheat Thylakoid Membranes
Author(s) -
Fei MeiJuan,
Chen JianSheng,
Wang XiaoYun
Publication year - 2006
Publication title -
journal of integrative plant biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.734
H-Index - 83
eISSN - 1744-7909
pISSN - 1672-9072
DOI - 10.1111/j.1744-7909.2006.00195.x
Subject(s) - thylakoid , phosphatase , chemistry , ethanol , phosphate , vanadate , uncompetitive inhibitor , biochemistry , membrane , non competitive inhibition , kinetics , enzyme , nuclear chemistry , chloroplast , physics , quantum mechanics , gene
A phosphatase that hydrolyses phosphate monoesters has been isolated from wheat thylakoid membranes. Biochemical properties and inhibition kinetics of the phosphatase were investigated using several ions, organic solvents, and inhibitors. Wheat ( Triticum aestivum L. cv. PH82‐2‐2) thylakoid membrane phosphatase activity was activated by Mg 2+ , Ca 2+ , and Fe 2+ and was inhibited by Mn 2+ and Cu 2+ . For example, enzyme activity was activated 34.81% by 2 mmol/L Mg 2+ , but was inhibited 22.3% and 8.5% by 2 and 1 mmol/L Cu 2+ , respectively. Methanol, ethanol and glycol were all able to activate enzyme activity. Enzyme activity was activated 58.5%, 48.2%, and 8.7% by 40% ethanol, methanol and glycol, respectively. From these results, it can be seen that the degree of activation of the phosphatase was greatest for ethanol and the type of activation was uncompetitive. Moreover, the activity of the thylakoid membrane phosphatase was inhibited by molybdate, vanadate, phosphate, and fluoride and the type of inhibition produced by these elements was uncompetitive, non‐competitive, competitive and mixed, respectively. (Managing editor: Ping He)