Vitelline coat of Unio elongatulus: II. Biochemical properties of the 220- and 180-kD components.
In a previous study we found that two glycoproteins with apparent molecular weights of 220 kD and 180 kD account for 80-90% of the material dissolved from the vitelline coat of the egg of the bivalve mollusk, Unio elongatulus (Focarelli and Rosati, 1993: Mol Reprod Dev 35:44-51). In this study we isolated and purified these glycoproteins by electroelution. The two proteins differ in many respects: the 180-kD molecule is acidic in nature and highly heterogeneous, whereas the 220-kD protein is neutral and less heterogeneous. Both seem to have O- and N-linked oligosaccharide chains. The 180-kD protein contains 13-16% carbohydrate, whereas the 220-kD molecular contains only 7-8%. Amino acid analysis and peptide mapping also show that each protein represents a unique polypeptide chain.
Focarelli
R
R
Department of Evolutionary Biology, University of Siena, Italy.
Santucci
A
A
Lampariello
R
R
Rosati
F
F
D000596:Amino Acids / Q000032:analysis; D000818:Animals; D002241:Carbohydrates / Q000032:analysis; D004527:Egg Proteins / Q000737:chemistry* / Q000302:isolation & purification; D015180:Electrophoresis, Gel, Two-Dimensional; D005260:Female; D006023:Glycoproteins / Q000737:chemistry* / Q000302:isolation & purification; D006031:Glycosylation; D008970:Molecular Weight; D008974:Mollusca / Q000737:chemistry*; D010449:Peptide Mapping; D014817:Vitelline Membrane / Q000737:chemistry*
D000596:Amino Acids; D002241:Carbohydrates; D004527:Egg Proteins; D006023:Glycoproteins