MetaCyc Reaction:

Superclasses: Reactions Classified By Conversion TypeSimple ReactionsChemical Reactions
Reactions Classified By SubstrateSmall-Molecule Reactions

EC Number:

The direction shown, i.e. which substrates are on the left and right sides, is in accordance with the direction in which it was curated.

Mass balance status: The left side is missing: Peptides: 2 . The right side is missing: Proteins: 1 O: 1 H: 1

Enzyme Commission Primary Name: spermosin

Taxonomic Range: Metazoa

Standard Gibbs Free Energy (ΔrG in kcal/mol): 36.144756Inferred by computational analysis [Latendresse13]

Enzyme Commission Summary:
Hydrolyzes arginyl bonds, preferably with Pro in the P2 position.

The enzyme from the ascidian (Prochordate) Halocynthia roretzi is localised in the sperm head, and released during sperm activation.

A proline-rich region is involved in binding to the vitelline coat of the egg.

Belongs to peptidase family S1.

Citations: [Sawada84, Sawada84a, Sawada96, Sawada96a]

Relationship Links: BRENDA:EC:, ENZYME:EC:, IUBMB-ExplorEnz:EC:


Latendresse13: Latendresse M. (2013). "Computing Gibbs Free Energy of Compounds and Reactions in MetaCyc."

Sawada84: Sawada H, Yokosawa H, Ishii S (1984). "Purification and characterization of two types of trypsin-like enzymes from sperm of the ascidian (Prochordata) Halocynthia roretzi. Evidence for the presence of spermosin, a novel acrosin-like enzyme." J Biol Chem 259(5);2900-4. PMID: 6365918

Sawada84a: Sawada H, Yokosawa H, Someno T, Saino T, Ishii S (1984). "Evidence for the participation of two sperm proteases, spermosin and acrosin, in fertilization of the ascidian, Halocynthia roretzi: inhibitory effects of leupeptin analogs on enzyme activities and fertilization." Dev Biol 105(1);246-9. PMID: 6381175

Sawada96: Sawada H, Iwasaki K, Kihara-Negishi F, Ariga H, Yokosawa H (1996). "Localization, expression, and the role in fertilization of spermosin, an ascidian sperm trypsin-like protease." Biochem Biophys Res Commun 222(2);499-504. PMID: 8670234

Sawada96a: Sawada H, Someno T (1996). "Substrate specificity of ascidian sperm trypsin-like proteases, spermosin and acrosin." Mol Reprod Dev 45(2);240-3. PMID: 8914083

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Please cite the following article in publications resulting from the use of MetaCyc: Caspi et al, Nucleic Acids Research 42:D459-D471 2014
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