GLUTATHIONE S-TRANSFERASES OF HUMAN SKIN - QUALITATIVE AND QUANTITATIVE DIFFERENCES IN MEN AND WOMEN

Glutathione S-transferase (GST) isozymes of male and female leg skin h ave been characterized. GST activities and protein have been quantifie d in a number of male and female skin samples and the results indicate that as compared to the male skin, female skin contains a higher amou nt of GST activity as well as protein. Both male and female leg skin c ontain three GST isozymes with pI values 9.9, 9.1 and 4.8. In accordan ce with previous findings the major isozyme, pI 4.8 belongs to the pi- class, whereas the two minor forms pI 9.1 and 9.9 belong to the alpha- class. Each of the three isozymes is more abundant in female skin. Sur prisingly, the specific activities and K(cat) values of the female ski n GSTs, particularly of the pi-class isozyme were found to be signific antly higher as compared to those of male skin isozyme. Studies into t he kinetics of inhibition by hematin also indicated differences in mal e and female skin GSTs. Whereas we confirm the presence of an alpha-cl ass GST, pI 9.9, in human skin with an apparently higher subunit M(r) value as compared to other human alpha-class GSTs, contrary to the pre vious report (Del Boccio ct al. (1987) Biochem. J. 244, 21-25), the re sults of the present studies show that the N-terminus of this alpha-cl ass GST is blocked.