线粒体NAD⁺糖水解酶的纯化及性质

Purification and properties of a mitochondrial NAD+ glycohydrolase.

作者信息

Moser B, Winterhalter K H, Richter C

出版信息

Arch Biochem Biophys. 1983 Jul 1;224(1):358-64. doi: 10.1016/0003-9861(83)90220-5.

Abstract

A 60- to 70-fold purification of an NAD+ glycohydrolase from the inner membrane of rat liver mitochondria to apparent homogeneity on sodium dodecyl sulfate (SDS)-polyacrylamide slab gel is described. The minimum molecular weight of the enzyme on polyacrylamide gels in the presence of SDS is around 62,000. The enzyme splits NAD+ to ADP-ribose and, presumably, nicotinamide. No phosphatase or phosphodiesterase activity is detected in the purified enzyme preparation. The enzyme shows high activity with NAD+ and moderate activity with NADP+ as substrates NAD(P)Hs are poor substrates. ATP and nicotinamide inhibit the enzyme. A possible participation of the enzyme in the mechanism of calcium release from rat liver mitochondria is discussed.

摘要

本文描述了从大鼠肝线粒体内膜中纯化出一种NAD⁺糖水解酶，在十二烷基硫酸钠（SDS）-聚丙烯酰胺平板凝胶上达到了约60至70倍的纯化，且纯度接近均一。在SDS存在的情况下，该酶在聚丙烯酰胺凝胶上的最小分子量约为62,000。该酶将NAD⁺分解为ADP-核糖，推测还有烟酰胺。在纯化的酶制剂中未检测到磷酸酶或磷酸二酯酶活性。该酶以NAD⁺为底物时表现出高活性，以NADP⁺为底物时表现出中等活性，而NAD(P)Hs是较差的底物。ATP和烟酰胺会抑制该酶。本文还讨论了该酶可能参与大鼠肝线粒体钙释放机制的情况。