PR00848

Sperm surface protein PH20

PRINTS entry
Member databasePRINTS
PRINTS typefamily
Short nameSPERMPH20

Description

O-Glycosyl hydrolases (EC 3.2.1.-) are a widespread group of enzymes that hydrolyse the glycosidic bond between two or more carbohydrates, or between a carbohydrate and a non-carbohydrate moiety. A classification system for glycosyl hydrolases, based on sequence similarity, has led to the definition of up to 60 different families
[4, 3, 2, 5]
(http://expasy.hcuge.ch/cgi-bin/lists?glycosid.txt). Family 56 encompasses a group of hyaluronidases (EC 3.2.1.35) that includes venom hyaluronidases and mammalian sperm surface proteins (PH-20).

PH-20 is required for sperm adhesion to the egg zona pellucida; it is located on both the sperm plasma membrane and acrosomal membrane
[1]
. During fertilisation, sperm must first penetrate a layer of cumulus cells that surrounds the egg, before reaching the zona pellucida. The cumulus cells are embedded in a matrix containing hyaluronic acid, which is formed prior to ovulation. PH-20 facilitates penetration of the cumulus cell layer by digesting hyaluronic acid.

The amino acid sequence of the mature protein contains 468 amino acids, and includes six potential N-linked glycosylation sites and twelve cysteines, eight of which are tightly clustered near the C-terminus
[1]
.

References

1.cDNA cloning reveals the molecular structure of a sperm surface protein, PH-20, involved in sperm-egg adhesion and the wide distribution of its gene among mammals. Lathrop WF, Carmichael EP, Myles DG, Primakoff P. J. Cell Biol. 111, 2939-49, (1990). View articlePMID: 2269661

2.Updating the sequence-based classification of glycosyl hydrolases. Henrissat B, Bairoch A. Biochem. J. 316 ( Pt 2), 695-6, (1996). View articlePMID: 8687420

3.New families in the classification of glycosyl hydrolases based on amino acid sequence similarities. Henrissat B, Bairoch A. Biochem. J. 293 ( Pt 3), 781-8, (1993). View articlePMID: 8352747

4.A classification of glycosyl hydrolases based on amino acid sequence similarities. Henrissat B. Biochem. J. 280 ( Pt 2), 309-16, (1991). View articlePMID: 1747104

5.Nucleotide sequences of the arb genes, which control beta-glucoside utilization in Erwinia chrysanthemi: comparison with the Escherichia coli bgl operon and evidence for a new beta-glycohydrolase family including enzymes from eubacteria, archeabacteria, and humans. el Hassouni M, Henrissat B, Chippaux M, Barras F. J. Bacteriol. 174, 765-77, (1992). View articlePMID: 1732212

This website requires cookies, and the limited processing of your personal data in order to function. By using the site you are agreeing to this as outlined in our Privacy Notice and Terms of Use.