Triton X-100 inhibition of yeast plasma membrane associated NADH-dependent redox activities |
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Authors: | Vineet Awasthi Snehlata Pandit Prakash C. Misra |
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Affiliation: | Department of Biochemistry, Lucknow University, -, 226 007, Lucknow, India |
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Abstract: | Plasma membrane (PM) vesicles isolated from the yeast Saccharomyces cerevisiae (wild-type NCIM 3078, and a MG 21290 mutant pma 1-1) were used to monitor the effect of the detergents, 3-[(3-cholamidopropyl) dimethylammonio]-1-propane sulfonate (Chaps) and Triton X-100, on H+-ATPase (E.C. 3.6.1.35), NADH oxidase and NADH- hexacynoferrate (III)[HCF (III)] oxidoreductase (E.C. 1.6.99.3) activities. The results obtained show that Triton X-100 inhibited both membrane bound and solubilized NADH-dependent redox activities. The nature of this inhibition as determined for NADH–HCF(III) oxidoreductase was non-competitive and the Ki values for wild and mutant enzymes were 1.2?×?10?5?M and 8.0?×?10?6?M, respectively. The findings are interpreted, in view of the established reports, that the active site architecture of PM bound NADH-dependent oxidoreductase in yeast is likely to be different than in other eukaryotes. |
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Keywords: | Saccharomyces cerevisiae plasma membrane H+-ATPase NADH-HCF(III) oxidoreductase triton X-100 inhibition chaps |
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