The localization of glycoprotein synthesis and storage was studied during acrosome formation in guinea-pig using fine-structure autoradiography after (3H)-fucose incorporation. Three days after (3H)-fucose injection, labelling in spermatids was concentrated in the matrix of developing acrosomes, and it was evident that the fucosylation of acrosomal glycoproteins largely overshadowed the fucosyl...

When proacrosin from mouse epididymal spermatozoa was activated a single form of acrosin was produced. The enzyme was isolated by gel filtration followed by affinity chromatography using Sepharose-4B linked to an acrosin inhibitor p-(p'-aminophenoxypropoxy)benzamidine. The molecular weight of partly purified acrosin was 53 000 by gel filtration, and of the pure enzyme 39 000 by SDS-polyacrylami...

Acrosin, a trypsin-like proteinase found in spermatozoa, is believed to play an essential role in fertilization by aiding the spermatozoon to penetrate the zona pellucida surrounding the egg (Mc Rorie and Williams, 1974). The precise cellular location of this enzyme is of considerable interest since such knowledge would aid in elucidating its mode of action. Biochemical studies have indicated t...

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...

Incubation of hamster eggs with trypsin or chymotrypsin, but not with a series of glycosidases or lipases, prevents capacitated spermatozoa from binding to the zona pellucida so that fertilization is prevented (Hartmann & Gwatkin, 1971 ; Gwatkin, Williams & Andersen, 1973). Inactivation of the binding sites for spermatozoa on the zona pellucida by a trypsin-like protease released by discharge o...

An acrosomal protein, sp32, was completely purified from acid extracts of ejaculated porcine sperm. Purified sp32 gave a single 32-kDa protein band on SDS-polyacrylamide gel electrophoresis and was characterized as a binding protein specific for 55-, 53-, and 49-kDa forms of (pro)acrosin. This protein was not capable of binding a 43-kDa acrosin intermediate and 35-kDa mature acrosin. sp32 signi...

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...

Two types of trypsin-like proteases, spermosin and acrosin, have been highly purified from spermatozoa of the ascidian (Prochordata) Hdocynthia roretzi by a procedure including diethylaminoethylcellulose chromatography, Sephadex G-100 gel filtration, and soybean trypsin inhibitor-immobilized Sepharose 4B chromatography. Each purified preparation was judged to be homogeneous on the basis of...

Mammalian sperm acrosomes contain a trypsin-like protease called acrosin which causes limited and specific hydrolysis of the extracellular matrix of the mammalian egg, the zona pellucida. Acrosin was localized on hamster, guinea-pig and human sperm using monoclonal and polyclonal antibodies to human acrosin labelled with colloidal gold. This was visualized directly with transmission electron mi...