Biomaterial Database

Studies on ram acrosin. Activation of proacrosin accompanying the isolation of acrosin from spermatozoa, and purification of the enzyme by affinity chromatography. 1978

C R Brown, and E F Hartree

1. A previously described, freeze-dried, partially purified ram acrosin preparation was fractionated on a column of Sepharose linked to the acrosin inhibitor p-(p'-aminophenoxypropoxy)benzamidine. Two acrosin fractions were obtained. 2. beta-Acrosin was homogeneous, quite stable at low pH and very stable when freeze-dried. Its molecular weight is about 38000, and it contains about six sugar residues per molecule, but no sialic acid. psi-Acrosin consisted of at least three unstable forms of acrosin. 3. When the entire purification process, starting from collection of semen, was carried out as rapidly as possible, the yield of beta-acrosin was increased and very little psi-acrosin was obtained. 4. In fresh ram semen the acrosin is present as the intra-acrosomal zymogen, proacrosin. After its extraction from spermatozoa autoproteolytic reactions convert proacrosin into beta-acrosin; psi-acrosin appears to be breakdown products of beta-acrosin. 5. When beta-acrosin was passed through a column of Sepharose linked to the non-inhibitory deamidinated analogue of the inhibitor it behaved as a hydrophobic protein. This is consistent with our view that acrosin (as zymogen) occurs in spermatozoa as a membrane-bound protein. 6. Success in the isolation of pure acrosin in high yield calls for an affinity adsorbent with the appropriate subsidiary hydrophobic properties.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D008970	Molecular Weight	The sum of the weight of all the atoms in a molecule.	Molecular Weights,Weight, Molecular,Weights, Molecular
D010450	Endopeptidases	A subclass of PEPTIDE HYDROLASES that catalyze the internal cleavage of PEPTIDES or PROTEINS.	Endopeptidase,Peptide Peptidohydrolases
D002241	Carbohydrates	A class of organic compounds composed of carbon, hydrogen, and oxygen in a ratio of Cn(H2O)n. The largest class of organic compounds, including STARCH; GLYCOGEN; CELLULOSE; POLYSACCHARIDES; and simple MONOSACCHARIDES.	Carbohydrate
D002846	Chromatography, Affinity	A chromatographic technique that utilizes the ability of biological molecules, often ANTIBODIES, to bind to certain ligands specifically and reversibly. It is used in protein biochemistry. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)	Chromatography, Bioaffinity,Immunochromatography,Affinity Chromatography,Bioaffinity Chromatography
D004589	Electrophoresis, Disc	Electrophoresis in which discontinuities in both the voltage and pH gradients are introduced by using buffers of different composition and pH in the different parts of the gel column. The term 'disc' was originally used as an abbreviation for 'discontinuous' referring to the buffers employed, and does not have anything to do with the shape of the separated zones.	Electrophoresis, Disk,Disc Electrophoresis,Disk Electrophoresis
D004789	Enzyme Activation	Conversion of an inactive form of an enzyme to one possessing metabolic activity. It includes 1, activation by ions (activators); 2, activation by cofactors (coenzymes); and 3, conversion of an enzyme precursor (proenzyme or zymogen) to an active enzyme.	Activation, Enzyme,Activations, Enzyme,Enzyme Activations
D004792	Enzyme Precursors	Physiologically inactive substances that can be converted to active enzymes.	Enzyme Precursor,Proenzyme,Proenzymes,Zymogen,Zymogens,Precursor, Enzyme,Precursors, Enzyme
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
D000596	Amino Acids	Organic compounds that generally contain an amino (-NH2) and a carboxyl (-COOH) group. Twenty alpha-amino acids are the subunits which are polymerized to form proteins.	Amino Acid,Acid, Amino,Acids, Amino