Activation of phospholipase A2 in rabbit erythrocyte membranes by a novel hemolytic toxin (H-toxin) of Clostridium septicum.
A primary effect of a novel H-toxin of Clostridium septicum on the hemolysis of rabbit erythrocytes was shown to be the activation of phospholipase A2 (PLA2) associated with rabbit erythrocyte membranes by 20-fold that of controls. Furthermore, the activation of PLA2 induced by the H-toxin was enhanced in the presence of NAD. The H-toxin itself had no PLA2 activity. On the contrary, the H-toxin bound to palmitic acid at a molar proportion of 1:1 and lost its hemolytic activity. The PLA2 was not activated by the H-toxin bound to palmitic acid. These results suggest that activation of the PLA2 is responsible for development of the hemolytic activity of the H-toxin.
Takano
S
S
Department of the Second Microbiology, Chiba University School of Medicine, Japan.
Noda
M
M
Kato
I
I
D000818:Animals; D001427:Bacterial Toxins / Q000378:metabolism / Q000494:pharmacology*; D003013:Clostridium; D004789:Enzyme Activation; D004910:Erythrocyte Membrane / Q000201:enzymology*; D006461:Hemolysis; D009243:NAD / Q000378:metabolism; D010169:Palmitic Acids / Q000378:metabolism; D010740:Phospholipases / Q000378:metabolism*; D010741:Phospholipases A / Q000378:metabolism*; D054467:Phospholipases A2; D011817:Rabbits
D001427:Bacterial Toxins; D010169:Palmitic Acids; C064270:hemolytic toxin, Clostridium septicum; D009243:NAD; D010740:Phospholipases; D010741:Phospholipases A; D054467:Phospholipases A2