[Kinetics of the proteolytic activity of intact human spermatozoa]

Seminal plasma free intact human washed spermatozoa have hydrolytic activity on N-benzoil-D-L-arginine-naftilamide (BANA). Kinetic activities of this enzymatic activity are similar to those described for acrosine. Therefore, it is likely that it would be the same enzyme. BANA- hydrolytic activity might be liberated to the medium by incubation of pH lower than 4.0 and reincorporates to the membrane after adjustment of the medium to alkaline pH. pH- dependant enzyme liberation curve is similar to titration curve of sialic acid attached to the membrane. Attachment of the enzyme to the spermatic membrane diminishes its specific activity. However, if spermatozoa are previously treated with neuraminidase, its membrane afinity is inhibited. It is thought that this enzyme in the spermatozoon is present as protein ionically bound to the membrane and that sialic acid participates in this union. It is postulated that drastic treatments such as the use of ultrasound or detergents produce redistribution of specific proteins.