Aminopeptidase in human seminal plasma

Aminopeptidase of seminal plasma was studied in normozoospermic, oligozoospermic, obstructive and non-obstructive azoospermic men. Significantly higher activity was observed in non-obstructive azoospermic patients than that of other three groups. L-Alanine beta-naphthylamide hydrochloride was found to have highest hydrolysis rate in comparison to various other aminoacyl beta-naphthylamide hydrochlorides which were used for determining substrate specificity. 50% inhibitions of the enzyme activity by EDTA and 1,10-phenanthroline were obtained at 5.77 X 10(-3) M and 3.13 X 10(-6) M concentrations respectively. A single band for aminopeptidase in the activity - gel electrophoresis was obtained for all the categories of seminal plasma and the enzyme exhibited the characteristics of metalloprotein.