Glutathione Reductase from Human Erythrocytes
Glutathione Reductase from Human Erythrocytes
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DOI：
10.1111/j.1432-1033.1976.tb10654.x
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发表时间：
1976-08
期刊：
影响因子：
5.4
通讯作者：
D. Worthington;M. Rosemeyer
中科院分区：
文献类型：
--
作者：
D. Worthington;M. Rosemeyer
人红细胞的谷胱甘肽还原酶在各种pH和离子强度条件下主要以100000分子量的实体存在。5.5 S的s20，w和50 μm2/s的D20，w与沉降平衡测定的分子量相关。该物种的同质性主要取决于硫醇的存在，其次是高浓度的盐。该酶的氨基酸组成显示出与其他来源的谷胱甘肽还原酶和硫辛酰胺脱氢酶的相似性。从黄素含量和十二烷基硫酸盐-聚丙烯酰胺电泳可以推断，天然酶是一个类似的亚基的分子量为50000组成的二聚体。在没有硫醇的情况下，谷胱甘肽还原酶显示出形成四聚体和更大聚集体的趋势。虽然这些较大的物种也具有催化活性，但在细胞条件下，其产物还原型谷胱甘肽的存在应使酶保持为二聚体实体。
Glutathione reductase from human erythrocytes exists predominantly as an entity of 100000 molecular weight under various conditions of pH and ionic strength. The s20,w of 5.5 S and D20,w of 50 μm2/s correlate with the molecular weight determined by sedimentation equilibrium. The homogeneity of this species is primarily dependent on the presence of thiols and secondarily on high concentrations of salt. The amino-acid composition of the enzyme shows similarities both with glutathione reductases from other sources and with lipoamide dehydrogenase. From the flavin content and dodecylsulphate-polyacrylamide electrophoresis it is inferred that the native enzyme is a dimer composed of similar subunits of 50000 molecular weight. In the absence of thiols, glutathione reductase shows a tendency to form tetramers and larger aggregates. Although these larger species are also catalytically active, under cellular conditions the presence of its product, reduced glutathione, should maintain the enzyme as the dimeric entity.