Aminopeptidase in human seminal plasma

Area of Science:

• Biochemistry
• Reproductive Biology
• Enzymology

Background:

• Seminal plasma contains enzymes crucial for reproductive function.
• Aminopeptidases play a role in seminal fluid physiology.
• Understanding enzyme activity in different male infertility statuses is important.

Purpose of the Study:

• To investigate seminal plasma aminopeptidase activity in various male infertility groups.
• To determine substrate specificity and inhibition patterns of seminal aminopeptidase.
• To characterize the nature of seminal aminopeptidase.

Main Methods:

• Assessing aminopeptidase activity in seminal plasma from normozoospermic, oligozoospermic, and azoospermic men (obstructive and non-obstructive).
• Evaluating substrate specificity using various aminoacyl beta-naphthylamide hydrochlorides.
• Determining enzyme inhibition using EDTA and 1,10-phenanthroline.
• Analyzing enzyme characteristics via activity gel electrophoresis.

Main Results:

• Significantly elevated aminopeptidase activity was found in non-obstructive azoospermic patients compared to other groups.
• L-Alanine beta-naphthylamide hydrochloride demonstrated the highest hydrolysis rate.
• EDTA and 1,10-phenanthroline inhibited enzyme activity at specific concentrations (5.77 x 10(-3) M and 3.13 x 10(-6) M, respectively).
• Activity gel electrophoresis revealed a single band for aminopeptidase across all seminal plasma categories, indicating a metalloprotein.

Conclusions:

• Seminal plasma aminopeptidase activity differs significantly across male infertility classifications, notably higher in non-obstructive azoospermia.
• The enzyme exhibits specific substrate preferences and metalloprotein characteristics.
• These findings contribute to understanding seminal plasma biochemistry in male infertility.