A novel 15 kDa Ca2+-binding protein present in the eggs of the sea urchin, Hemicentrotus pulcherrimus.
A novel Ca2+-binding protein, different from calmodulin, has been purified to homogeneity from the soluble cytoplasmic protein fraction of the egg of the sea urchin, Hemicentrotus pulcherrimus. This protein, designated as 15 kDa protein, shows a Ca2+-dependent mobility shift upon SDS-gel electrophoresis and has Ca2+-binding ability. This protein did not resemble the sea urchin egg calmodulin in either molecular mass or amino acid composition. The 15 kDa protein could not activate cyclic adenosine 3',5'-monophosphate-dependent phosphodiesterase from bovine brain and did not bind to fluphenazine-Sepharose 6B. Antibodies against the 15 kDa protein did not react with sea urchin egg calmodulin. These results suggest that the 15 kDa protein is a novel Ca2+-binding protein in the sea urchin egg.
D000596:Amino Acids / Q000032:analysis; D000818:Animals; D017317:Annexin A6; D002135:Calcium-Binding Proteins / Q000302:isolation & purification*; D002147:Calmodulin / Q000032:analysis; D002846:Chromatography, Affinity; D004591:Electrophoresis, Polyacrylamide Gel; D007120:Immunochemistry; D008970:Molecular Weight; D010063:Ovum / Q000032:analysis*; D012617:Sea Urchins
D000596:Amino Acids; D017317:Annexin A6; D002135:Calcium-Binding Proteins; D002147:Calmodulin