Di Ilio C, Aceto A, Piccolomini R, Allocati N, Faraone A, Cellini L, Ravagnan G, Federici G
Istituti di Scienze Biochimiche, Facoltà di Medicina, Università G. D'Annunzio, Roma, Italy.
Biochem J. 1988 Nov 1;255(3):971-5. doi: 10.1042/bj2550971.
Three forms of glutathione transferase (GST) with pI values of 6.0, 6.4 and 7.3 were isolated from Proteus mirabilis AF 2924 by glutathione-affinity chromatography followed by isoelectric focusing, and their structural, kinetic and immunological properties were investigated. Upon SDS/polyacrylamide-slab-gel electrophoresis, all forms proved to be composed of two subunits of identical (22,500) Mr. GST-6.0 and GST-6.4 together account for about 95% of the total activity, whereas GST-7.3 is present only in trace amounts. Extensive similarities have been found between GST-6.0 and GST-6.4. These include subunit molecular mass, amino acid composition, substrate specificities and immunological characteristics. GST-7.3 also cross-reacted (non-identity) with antisera raised against bacterial GST-6.0. None of the antisera raised against a number of human, rat and mouse GSTs cross-reacted with the bacterial enzymes, indicating major structural differences between them and the mammalian GSTs. This conclusion is further supported by c.d. spectra.
通过谷胱甘肽亲和层析继以等电聚焦，从奇异变形杆菌AF 2924中分离出三种等电点分别为6.0、6.4和7.3的谷胱甘肽转移酶（GST），并对其结构、动力学和免疫学特性进行了研究。在SDS/聚丙烯酰胺平板凝胶电泳中，所有形式均被证明由两个分子量相同（22,500）的亚基组成。GST-6.0和GST-6.4共同占总活性的约95%，而GST-7.3仅以痕量存在。已发现GST-6.0和GST-6.4之间存在广泛相似性。这些包括亚基分子量、氨基酸组成、底物特异性和免疫学特征。GST-7.3也与针对细菌GST-6.0产生的抗血清发生交叉反应（非同一性）。针对多种人、大鼠和小鼠GST产生的抗血清均未与细菌酶发生交叉反应，表明它们与哺乳动物GST之间存在主要结构差异。圆二色光谱进一步支持了这一结论。
