title: Phospholipase A2 activity in ram spermatozoa plasma membranes.
abstract: A highly active phospholipase A2 in ram spermatozoa plasma membranes has been established. Phospholipase A2 was optimally active at pH 7.4 and was Ca2+ dependent. Low concentrations of K+ (25 mM) were found to inhibit phospholipase A2 activity, whereas higher concentrations induced enzyme reactivation. An inhibitory effect of Zn2+ has also been observed.
mesh_terms: D000818:Animals; D002118:Calcium / Q000494:pharmacology; D002462:Cell Membrane / Q000201:enzymology; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008297:Male; D010740:Phospholipases / Q000378:metabolism*; D010741:Phospholipases A / Q000037:antagonists & inhibitors / Q000378:metabolism*; D054467:Phospholipases A2; D011188:Potassium / Q000494:pharmacology; D012756:Sheep / Q000378:metabolism*; D013094:Spermatozoa / Q000201:enzymology*; D015032:Zinc / Q000494:pharmacology
chemical_list: D010740:Phospholipases; D010741:Phospholipases A; D054467:Phospholipases A2; D015032:Zinc; D011188:Potassium; D002118:Calcium