吲哚乙酸和N6-（δ2-异戊烯基）腺嘌呤影响NADH与酵母乙醇脱氢酶的结合，并在体外抑制乙醇的酶促氧化。

Indolylacetic acid and N6-(delta 2-isopentenyl) adenine affect NADH binding to yeast alcohol dehydrogenase and inhibit in vitro the enzymatic oxidation of ethanol.

作者信息

Zikmanis P, Krüce R

机构信息

August Kirchenstein Institute of Microbiology, Latvian Academy of Sciences, Ríga, USSR.

出版信息

Biofactors. 1990 Oct;2(4):237-40.

PMID:2282140

Abstract

Derivative UV spectroscopic data show that the plant growth substances N6-(delta 2-isopentenyl) adenine (i6Ade) and indolylacetic acid (IAA) can bind to the yeast alcohol dehydrogenase (ADH) and affect coenzyme-enzyme binding. This is confirmed by enzyme kinetics studies. At fixed ethanol concentrations (27.8 and 111.1 mM) and varying NAD+ concentrations (0.033-2 mM), as well as at fixed levels of coenzyme (0.67 and 2 mM), and at varying concentrations of ethanol (1.4-111.1 mM), the rate of ethanol oxidation is significantly inhibited by i6Ade and IAA. The kinetics of the ADH reaction is affected by two inhibition constants (KI and K'I) which correspond to the dissociation constants of complexes EI and ESI, respectively. For i6Ade the KI = 0.52 +/- 0.06 mM and K'I = 0.74 +/- 0.07 mM, and for IAA the KI = 0.88 +/- 0.03 mM and K'I = 0.99 +/- 0.02 mM.

摘要

衍生紫外光谱数据表明，植物生长物质N6-（δ2-异戊烯基）腺嘌呤（i6Ade）和吲哚乙酸（IAA）能够与酵母乙醇脱氢酶（ADH）结合，并影响辅酶与酶的结合。酶动力学研究证实了这一点。在固定乙醇浓度（27.8和111.1 mM）和不同NAD+浓度（0.033 - 2 mM）下，以及在固定辅酶水平（0.67和2 mM）和不同乙醇浓度（1.4 - 111.1 mM）下，i6Ade和IAA显著抑制乙醇氧化速率。ADH反应的动力学受两个抑制常数（KI和K'I）影响，它们分别对应于复合物EI和ESI的解离常数。对于i6Ade，KI = 0.52 ± 0.06 mM，K'I = 0.74 ± 0.07 mM；对于IAA，KI = 0.88 ± 0.03 mM，K'I = 0.99 ± 0.02 mM。