[来自牛肝的酪氨酰 - tRNA合成酶。分离及理化性质]

[Tyrosyl-tRNA synthetase from the bovine liver. Isolation and physico-chemical properties].

作者信息

Korneliuk A I, Kurochkin I V, Matsuka G Kh

出版信息

Mol Biol (Mosk). 1988 Jan-Feb;22(1):176-86.

Abstract

Tyrosyl-tRNA synthetase of beef liver has been isolated and its properties have been studied. Tyrosyl-tRNA synthetase is a structural dimer of alpha 2 type. Mr of the enzyme subunit is about 59 kDa. Km values for substrates have been determined and compared with kinetic properties of tyrosyl-tRNA synthetases from different sources. The polymorphism of tyrosyl-tRNA synthetase was studied. The enzyme was separated into two different forms by chromatography on phosphocellulose P 11. P1-form is active only in the amino acid activation reaction. This form is not due to the phosphorylation of the enzyme. The low molecular weight form (38 kDa) was also isolated. This form appeared due to the limited endogenic proteolysis of the main form and retained full activity in the aminoacylation reaction. Tyrosyl-tRNA synthetase from beef liver has non-specific affinity to rRNA-sepharose.

摘要

牛肝酪氨酰 - tRNA合成酶已被分离出来并对其性质进行了研究。酪氨酰 - tRNA合成酶是α2型结构二聚体。该酶亚基的相对分子质量约为59 kDa。已测定底物的米氏常数，并与来自不同来源的酪氨酰 - tRNA合成酶的动力学性质进行了比较。研究了酪氨酰 - tRNA合成酶的多态性。通过在磷酸纤维素P11上进行色谱分离，该酶被分为两种不同形式。P1形式仅在氨基酸活化反应中具有活性。这种形式不是由于酶的磷酸化。还分离出了低分子量形式（38 kDa）。这种形式是由于主要形式的有限内源性蛋白水解而出现的，并且在氨酰化反应中保留了全部活性。牛肝酪氨酰 - tRNA合成酶对rRNA - 琼脂糖具有非特异性亲和力。