Biochemistry and Biophysics Section, Biological Sciences Group, University of Connecticut, Storrs, Connecticut 06268.
Plant Physiol. 1978 Jan;61(1):107-10. doi: 10.1104/pp.61.1.107.
Extracts of light-grown Cucumis sativus L. seedlings catalyzed the oxidation of indole-3-acetaldehyde to indole-3-acetic acid. No added cofactors were required. Inhibitor studies indicated that the enzyme is a metalloflavoprotein. While indole-3-aldehyde, benzaldehyde, and phenylacetaldehyde partially inhibited the oxidation of indole-3-acetaldehyde, suggesting that they may serve as alternative substrates, it is proposed that indoleacetaldehyde is the major substrate in vivo. 2,4-Dichlorophenoxyacetic acid strongly inhibited the indoleacetaldehyde oxidase activity, and it is proposed that this enzyme may be subject in vivo to feedback inhibition by indole-3-acetic acid. The enzyme was activated by brief heating or by treatment with mercaptoethanol.
光培养的黄瓜幼苗提取物催化吲哚-3-乙醛氧化为吲哚-3-乙酸。不需要添加辅助因子。抑制剂研究表明，该酶是一种金属黄素蛋白。虽然吲哚-3-醛、苯甲醛和苯乙醛部分抑制了吲哚-3-乙醛的氧化，表明它们可能作为替代底物，但推测吲哚乙醛是体内的主要底物。2,4-二氯苯氧乙酸强烈抑制吲哚乙醛氧化酶的活性，因此推测该酶可能在体内受到吲哚-3-乙酸的反馈抑制。该酶通过短暂加热或巯基乙醇处理而被激活。
