5-甲基硫代核糖1-磷酸：部分纯化的大鼠肝脏5'-甲基硫代腺苷磷酸化酶活性的产物。

5-methylthioribose 1-phosphate: a product of partially purified, rat liver 5'-methylthioadenosine phosphorylase activity.

作者信息

Ferro A J, Wrobel N C, Nicolette J A

出版信息

Biochim Biophys Acta. 1979 Sep 12;570(1):65-73. doi: 10.1016/0005-2744(79)90201-8.

Abstract

5'-Methylthioadenosine phosphorylase from rat liver has been purified 112-fold. A molecular weight of 90 000 for the enzyme was estimated from gel filtration on Sephadex G-150. The Km for 5'-methylthioadenosine was 4.7 . 10(-7) M, while the Km for phosphate was 2 . 10(-4) M. The products of the reaction were isolated and identified as adenine and 5-methylthioribose 1-phosphate. In addition to 5'-methylthioadenosine the nucleoside analogues 5'-ethylthioadenosine and 5'-n-propylthioadenosine also served as substrates for the enzyme. The 7-deaza analogue 5'-methylthiotubercidin was found to be an inhibitor of the reaction, but was inactive as a substrate.

摘要

大鼠肝脏中的5'-甲硫基腺苷磷酸化酶已被纯化了112倍。通过在Sephadex G-150上进行凝胶过滤，估计该酶的分子量为90000。5'-甲硫基腺苷的米氏常数为4.7×10⁻⁷ M，而磷酸盐的米氏常数为2×10⁻⁴ M。反应产物被分离并鉴定为腺嘌呤和5-甲硫基核糖1-磷酸。除了5'-甲硫基腺苷外，核苷类似物5'-乙硫基腺苷和5'-正丙硫基腺苷也可作为该酶的底物。发现7-脱氮类似物5'-甲硫基杀结核菌素是该反应的抑制剂，但作为底物无活性。