title: In vitro aggregation of platelets induced by alpha-toxin (phospholipase C) of Clostridium perfringens.
abstract: Highly purified alpha-toxin (phospholipase C) of Clostridium perfringens prepared by affinity chromatography on agarose-linked egg-yolk lipoprotein induced the in vitro aggregation of platelets of an irreversible type. The aggregation started after a time lag, the length of which depended on the concentration of the toxin; the reciprocal of the time lag was found to be directly proportional to the toxin concentration. Using this assay method, we demonstrated that the platelet-aggregating activity of alpha-toxin reached minimum at around 70 C but heating at higher temperatures inactivated it to a lesser extent; the same anomaly in heat inactivation was observed with phospholipase C activity possessed by the toxin. By subjecting purified alpha-toxin to isoelectric focusing, four molecular forms were isolated, all of which were associated with both the platelet-aggregating and phospholipase C activities. From all these results we concluded that the entity responsible for the platelet-aggregating activity is identical with alpha-toxin (phospholipase C).
mesh_terms: D000818:Animals; D001427:Bacterial Toxins / Q000302:isolation & purification / Q000494:pharmacology*; D002417:Cattle; D002846:Chromatography, Affinity; D003016:Clostridium perfringens / Q000032:analysis*; D004305:Dose-Response Relationship, Drug; D006358:Hot Temperature; D007525:Isoelectric Focusing; D010740:Phospholipases / Q000494:pharmacology*; D010974:Platelet Aggregation / Q000187:drug effects*; D012710:Serum Albumin, Bovine
chemical_list: D001427:Bacterial Toxins; D012710:Serum Albumin, Bovine; D010740:Phospholipases