卤虫胚胎的胞质5'-核苷酸酶。纯化及性质

Cytosol 5'-nucleotidase from Artemia embryos. Purification and properties.

作者信息

Pinto R M, Canales J, Faraldo A, Sillero A, Günther Sillero M A

出版信息

Comp Biochem Physiol B. 1987;86(1):49-53. doi: 10.1016/0305-0491(87)90173-8.

Abstract

Cytosol 5'-nucleotidase (EC 3.1.3.5) has been purified near homogeneity from Artemia embryos. The enzyme cleaves preferentially IMP and GMP, and to a lesser extent other 5'-mononucleotides. The substrate-velocity plot was hyperbolic with GMP and sigmoidal with AMP. The hydrolysis of GMP is stimulated both by ATP and beta, gamma-methyleneadenosine 5'-triphosphate with the same activation constant of around 0.6 mM. Both nucleotides decreased S0.5 without affecting V. The molecular mass of the native purified enzyme was 165 kDa, and one major band of 42 kDa was detected after sodium dodecyl sulphate polyacrylamide gel electrophoresis.

摘要

已从卤虫胚胎中近乎纯一地纯化出胞质溶胶5'-核苷酸酶（EC 3.1.3.5）。该酶优先切割肌苷酸（IMP）和鸟苷酸（GMP），对其他5'-单核苷酸的切割程度较小。底物-速度曲线对GMP呈双曲线，对腺苷酸（AMP）呈S形曲线。ATP和β,γ-亚甲基腺苷5'-三磷酸均能刺激GMP的水解，其激活常数相同，约为0.6 mM。这两种核苷酸均降低了S0.5，而不影响V。纯化后的天然酶的分子量为165 kDa，在十二烷基硫酸钠聚丙烯酰胺凝胶电泳后检测到一条42 kDa的主要条带。