Intra-acrosomal inhibition of boar acrosin by synthetic proteinase inhibitors

Boar acrosin. II. Classification, inhibition, and specificity studies of a proteinase from sperm acrosomes.

Acrosin, a proteolytic enzyme located in the acrosome of sperm, exhibits amidase, esterase, and proteinase activity on synthetic and natural substrates containing arginyl and lysyl residues. Highly purified acrosin preparations from boar acrosomes have endopeptidase activity cleaving only the carboxyl bonds of arginine and lysine with a strong preference for arginine bonds. The Michaelis consta...

Boar acrosin. I. Purification and preliminary characterization of a proteinase from boar sperm acrosomes.

Acrosin is a proteolytic enzyme used by sperm to digest a path through the zona pellucida of the ovum. In ejaculated sperm it is inactivated by a proteinase inhibitor from seminal plasma that also inhibits trypsin. This inhibitor is removed or inactivated during the residence in the female reproductive tract as a part of the capacitation process. The boar acrosin-inhibitor complex was partially...

Interaction of human sperm acrosomal proteinase with human seminal plasma proteinase inhibitors.

Immunocytochemical detection of acrosomal damage following cold shock: loss of acrosin from the acrosomal region of ram, bull and boar spermatozoa.

Samples of ram, bull and boar semen were subjected to cold shock and then stained using an indirect immunocytochemical method for detecting acrosin. It was found that the shock treatment abolished staining of the acrosomal region in all but a very few cells. This finding was interpreted as a great loss of proacrosin or acrosin from damaged acrosomes. Using a fluorescent label in the system, spe...

Heparin protects cathepsin G against inhibition by protein proteinase inhibitors.

Cathepsin G, a cationic serine proteinase present in neutrophils and monocytes, is able to cleave biologically important proteins and may thus participate in tissue destruction during inflammation. Its activity is physiologically controlled by the fast-acting serpins, alpha 1-anti-chymotrypsin (ka = 5 x 10(7) M-1 S-1) and alpha 1-proteinase inhibitor (ka = 2.7 x 10(5) M-1 S-1). We have shown th...