Activation of Purified Human Plasma Prekallikrein Triggered by Cell Wall Fractions of Escherichia coli and Staphylococcus aureus

Abstract

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 (M_r) 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 0111B4 induced 50%–90% optimal activity. However, the polysaccharide fraction induced 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-M_r kininogen.