Di Ilio C, Aceto A, Del Boccio G, Casalone E, Pennelli A, Federici G
Istituto di Scienze Biochimiche, Facoltà di Medicina, Università G. D'Annunzio, Chieti, Italy.
Eur J Biochem. 1988 Feb 1;171(3):491-6. doi: 10.1111/j.1432-1033.1988.tb13816.x.
Five glutathione transferase (GST) forms were purified from human uterus by glutathione-affinity chromatography followed by chromatofocusing, and their structural, kinetic and immunological properties were investigated. Upon SDS/polyacrylamide slab gel electrophoresis all forms resulted composed of two subunits of identical molecular size. GST V (pI 4.5) is a dimer of 23-kDa subunits. GST I (pI 6.8) and GST IV (pI 4.9) are dimers of 24-kDa subunits whereas GST II (pI 6.1) and GST III (pI 5.5) are dimers of 26.5-kDa subunits. GST V accounts for about 85-90% of the activity whereas the other isoenzymes are present in trace quantities. On the basis of the molecular mass of the subunits, amino acid composition, substrate specificities, sensitivities to inhibitors, CD spectra and immunological studies, GST V appeared very similar to transferase pi. Structural and immunological studies provide evidence that GST IV is closely related to the less 'basic' transferase (GST pI 8.5) of human skin. Extensive similarities have been found between GST II and GST III. The comparison includes amino acid compositions, subunits molecular size and immunological properties. The two enzymes, however, are kinetically distinguishable. The data presented also indicate that GST II and GST III are related to transferase mu and to transferase psi of human liver. Even though GST I has a subunit molecular mass identical to GST IV, several lines of evidence, including catalytic and immunological properties, indicate that they are different from each other. GST I seems not to be related to any of known human transferases, suggesting that it may be specific for the uterus.
通过谷胱甘肽亲和层析继以层析聚焦法从人子宫中纯化出五种谷胱甘肽转移酶（GST）形式，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，所有形式均由两个分子大小相同的亚基组成。GST V（pI 4.5）是由23 kDa亚基组成的二聚体。GST I（pI 6.8）和GST IV（pI 4.9）是由24 kDa亚基组成的二聚体，而GST II（pI 6.1）和GST III（pI 5.5）是由26.5 kDa亚基组成的二聚体。GST V占活性的约85 - 90%，而其他同工酶以痕量存在。基于亚基的分子量、氨基酸组成、底物特异性、对抑制剂的敏感性、圆二色光谱和免疫学研究，GST V与转移酶π非常相似。结构和免疫学研究提供证据表明GST IV与人皮肤中碱性较弱的转移酶（GST pI 8.5）密切相关。已发现GST II和GST III之间存在广泛相似性。比较包括氨基酸组成、亚基分子大小和免疫学特性。然而，这两种酶在动力学上是可区分的。所呈现的数据还表明GST II和GST III与人肝脏的转移酶μ和转移酶ψ相关。尽管GST I的亚基分子量与GST IV相同，但包括催化和免疫学特性在内的多条证据表明它们彼此不同。GST I似乎与任何已知的人转移酶都无关，这表明它可能对子宫具有特异性。
