title: Inhibition of Bacillus cereus phospholipase C by univalent anions.
abstract: The rate of phospholipid hydrolysis in erythrocyte ghosts by Bacillus cereus phospholipase C was markedly decreased by the presence of NaCl at concentrations between 25 and 200 mM. The inhibition seemed to be due to Cl- and was unaffected by the type of cation present. The larger univalent anions such as HCO3-, Br-, Cl-, NO3-, CNO- and I- seemed most effective, whereas the bivalent anion SO42- was relatively ineffective at 0.1 M, as were acetate and formate. Tris buffers at 0.1 M caused marked inhibition. With bovine brain myelin, phospholipid hydrolysis by phospholipase C was also much more strongly inhibited by I- and Cl- than by SO42- or acetate. NaCl inhibited the hydrolysis by the enzyme of the soluble substrate dihexanoylglycerophosphocholine, thereby suggesting that the inhibiton did not arise simply from substrate effects.
mesh_terms: D000838:Anions / Q000494:pharmacology*; D001409:Bacillus cereus / Q000201:enzymology*; D004910:Erythrocyte Membrane / Q000378:metabolism; D006801:Humans; D010740:Phospholipases / Q000037:antagonists & inhibitors*; D010743:Phospholipids / Q000097:blood; D012965:Sodium Chloride / Q000494:pharmacology; D010738:Type C Phospholipases / Q000037:antagonists & inhibitors*
chemical_list: D000838:Anions; D010743:Phospholipids; D012965:Sodium Chloride; D010740:Phospholipases; D010738:Type C Phospholipases