化学交联可稳定甲酰四氢叶酸合成酶的酶活性和四级结构。

Chemical cross-linking stabilizes the enzymic activity and quaternary structure of formyltetrahydrofolate synthetase.

作者信息

de Renobales M, Welch W

出版信息

J Biol Chem. 1980 Nov 10;255(21):10460-3.

Abstract

Clostridium cylindrosporum formyltetrahydrofolate synthetase tetramers cross-linked with dimethyl suberimidate remained active in the absence of the monovalent cations normally required for enzymic activity and the tetrameric conformation. The modified enzyme was analyzed by sodium dodecyl sulfate electrophoresis, sedimentation velocity, and gel permeation chromatography. Under the experimental conditions used, the enzyme was only partially cross-linked; 74% of the enzyme was cross-linked dimer or monomer. Nonetheless, the modified enzyme is able to retain enzymic activity and the tetrameric structure under conditions where native enzyme would be completely dissociated and inactivated. The result suggests that cross-linked dimers strongly associate with each other and with monomers. Flame emission spectroscopy indicates that cross-linked enzyme contains two monovalent cations per tetramer.

摘要

用亚胺二甲酯交联的柱状芽孢梭菌甲酰四氢叶酸合成酶四聚体，在缺乏酶活性和四聚体构象通常所需的一价阳离子的情况下仍保持活性。通过十二烷基硫酸钠电泳、沉降速度和凝胶渗透色谱法对修饰后的酶进行了分析。在所使用的实验条件下，该酶仅部分交联；74%的酶交联成二聚体或单体。尽管如此，修饰后的酶在天然酶会完全解离并失活的条件下仍能保持酶活性和四聚体结构。结果表明，交联的二聚体彼此之间以及与单体之间强烈缔合。火焰发射光谱表明，交联酶每个四聚体含有两个一价阳离子。