Biomaterial Database

The histochemical localization of acrosin in guinea-pig sperm after the acrosome reaction. 1978

D P Green, and A R Hockaday

The protease acrosin is widely considered to be an essential component of a zona lysin which enables sperm to penetrate the zona pellucida of the egg. Sperm form a characteristic penetration slit little wider than the sperm head itself and this has long suggested that any zona lysin is attached to the sperm surface after an acrosome reaction. This paper provides the first ultrastructural evidence that this is the case. The protein acrosin inhibitor, Kunitz soybean trypsin inhibitor, has been covalently attached to the electron-dense marker, ferritin, and the conjugate incubated with guinea-pig sperm which have undergone an A23187-induced acrosome reaction. Electron microscopy shows that ferritin is distributed unevenly over the outer surface of the newly exposed inner acrosomal membrane but does not extend to the equatorial segment. This is further evidence that acrosin can be considered as a candidate for the role of zona lysin. The mechanism of sperm penetration of the zona is discussed in the light of these observations.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D008854	Microscopy, Electron	Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.	Electron Microscopy
D010450	Endopeptidases	A subclass of PEPTIDE HYDROLASES that catalyze the internal cleavage of PEPTIDES or PROTEINS.	Endopeptidase,Peptide Peptidohydrolases
D002462	Cell Membrane	The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.	Plasma Membrane,Cytoplasmic Membrane,Cell Membranes,Cytoplasmic Membranes,Membrane, Cell,Membrane, Cytoplasmic,Membrane, Plasma,Membranes, Cell,Membranes, Cytoplasmic,Membranes, Plasma,Plasma Membranes
D006168	Guinea Pigs	A common name used for the genus Cavia. The most common species is Cavia porcellus which is the domesticated guinea pig used for pets and biomedical research.	Cavia,Cavia porcellus,Guinea Pig,Pig, Guinea,Pigs, Guinea
D006651	Histocytochemistry	Study of intracellular distribution of chemicals, reaction sites, enzymes, etc., by means of staining reactions, radioactive isotope uptake, selective metal distribution in electron microscopy, or other methods.	Cytochemistry
D000001	Calcimycin	An ionophorous, polyether antibiotic from Streptomyces chartreusensis. It binds and transports CALCIUM and other divalent cations across membranes and uncouples oxidative phosphorylation while inhibiting ATPase of rat liver mitochondria. The substance is used mostly as a biochemical tool to study the role of divalent cations in various biological systems.	4-Benzoxazolecarboxylic acid, 5-(methylamino)-2-((3,9,11-trimethyl-8-(1-methyl-2-oxo-2-(1H-pyrrol-2-yl)ethyl)-1,7-dioxaspiro(5.5)undec-2-yl)methyl)-, (6S-(6alpha(2S,3S),8beta(R*),9beta,11alpha))-,A-23187,A23187,Antibiotic A23187,A 23187,A23187, Antibiotic
D000176	Acrosin	A trypsin-like enzyme of spermatozoa which is not inhibited by alpha 1 antitrypsin.	Acrosomal proteinase,Akrosin,M beta-Acrosin,M beta Acrosin,beta-Acrosin, M,proteinase, Acrosomal
D000177	Acrosome	The cap-like structure covering the anterior portion of SPERM HEAD. Acrosome, derived from LYSOSOMES, is a membrane-bound organelle that contains the required hydrolytic and proteolytic enzymes necessary for sperm penetration of the egg in FERTILIZATION.	Acrosomes
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia