Madyastha K M, Gururaja T L
Department of Organic Chemistry, Indian Institute of Science, Bangalore.
Biochem Biophys Res Commun. 1995 Jun 15;211(2):540-6. doi: 10.1006/bbrc.1995.1847.
Alcaligenes eutrophus utilizing nerolidol, a sesquiterpene alcohol, as the sole source of carbon contains an inducible NAD(P)(+)-linked secondary alcohol dehydrogenase (SADH). The enzyme was purified to homogeneity by a combination of salt precipitation, ion exchange and affinity matrix chromatographies. The apparent molecular mass of the enzyme was estimated to be 139 KDa with four identical subunits of 38.5 KDa. The enzyme carried out both oxidation and reduction reactions. At pH 5.5, enzyme catalyzed the stereospecific reduction of prochiral ketones to secondary alcohols. The pH optimum for the oxidation reaction was 9.5. NADP+ and NADPH were respectively preferred over NAD+ and NADH for oxidation and reduction reactions. Some of the properties of this enzyme were found to be significantly different from those thus far described.
利用倍半萜醇橙花叔醇作为唯一碳源的真养产碱菌含有一种可诱导的NAD(P)(+)连接的仲醇脱氢酶（SADH）。通过盐析、离子交换和亲和基质色谱相结合的方法将该酶纯化至同质。该酶的表观分子量估计为139 kDa，由四个38.5 kDa的相同亚基组成。该酶能进行氧化和还原反应。在pH 5.5时，酶催化前手性酮立体特异性还原为仲醇。氧化反应的最适pH为9.5。对于氧化和还原反应，NADP+和NADPH分别比NAD+和NADH更受青睐。发现该酶的一些性质与迄今为止所描述的性质有显著不同。
