构巢曲霉和黑曲霉中依赖NADP(+)的甘油脱氢酶的纯化及性质

Purification and properties of NADP(+)-dependent glycerol dehydrogenases from Aspergillus nidulans and A. niger.

作者信息

Schuurink R, Busink R, Hondmann D H, Witteveen C F, Visser J

机构信息

Department of Genetics, Agricultural University, Wageningen, The Netherlands.

出版信息

J Gen Microbiol. 1990 Jun;136(6):1043-50. doi: 10.1099/00221287-136-6-1043.

DOI:10.1099/00221287-136-6-1043

PMID:2200840

Abstract

Glycerol dehydrogenase, NADP(+)-specific (EC 1.1.1.72), was purified from mycelium of Aspergillus nidulans and Aspergillus niger using different purification procedures. Both enzymes had an Mr of approximately 38,000 and were immunologically cross-reactive, but had different amino acid compositions and isoelectric points. For both enzymes, the substrate specificity was limited to glycerol and erythritol for the oxidative reaction and to dihydroxyacetone (DHA), diacetyl, methylglyoxal, erythrose and D-glyceraldehyde for the reductive reaction. The A. nidulans enzyme had a turnover number twice that of the A. niger enzyme at pH 6.0, whereas inhibition by NADP+ was less (Ki = 45 microM vs 13 microM). It is proposed that both enzymes catalyse in vivo the reduction of DHA to glycerol and that they are regulated by the anabolic reduction charge.

摘要

从构巢曲霉和黑曲霉的菌丝体中采用不同的纯化程序纯化出了NADP(+)-特异性甘油脱氢酶（EC 1.1.1.72）。两种酶的相对分子质量均约为38,000，具有免疫交叉反应性，但氨基酸组成和等电点不同。对于这两种酶，氧化反应的底物特异性仅限于甘油和赤藓醇，还原反应的底物特异性仅限于二羟基丙酮（DHA）、双乙酰、甲基乙二醛、赤藓糖和D-甘油醛。在pH 6.0时，构巢曲霉的酶的转换数是黑曲霉的酶的两倍，而NADP+的抑制作用较小（抑制常数分别为45 μM和13 μM）。有人提出，这两种酶在体内催化DHA还原为甘油，并且它们受合成代谢还原电荷的调节。