Whether Escherichia coli and Staphylococcus aureus cell wall fractions can trigger the activation of prekallikrein was investigated in a mixture of purified human factor XII, prekallikrein, and high-relative-molecular-weight (Mr) kininogen. After exposure for 30 min to bacterial preparations (0.02-5 mg/ml) at 0 C, lallikrein amidolytic activity was expressed as a percentage of the optimal activation of prekallikrein induced by dextran sulfate. Lipopolysaccharide (LPS) fractions of five E coli strains and lipid A of E coli O111B4 induced 50%-90% optimal activity. However, the polysaccharide fraction induced less than 5% activity. Peptidoglycan and teichoic acid of S aureus induced 70%-100% optimal activity at 5 mg/ml, but protein A did not generate activity. No activation of prekallikrein occurred in the absence of factor XII. Thus, LPS and lipid A of E coli and peptidoglycan and teichoic acid of S aureus can generate kallikrein amidolytic activity in a mixture of purified factor XII, prekallikrein, and high-Mr kininogen.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.