The activation of the alternative pathway C3 convertase by human plasma kallikrein.
Human plasma kallikrein can replace factor D for the activation of the alternative pathway C3 convertase of human complement. The factor B cleavage patterns by factor D and kallikrein are indistinguishable. The ability of kallikrein to cleave factor B is influenced by the magnesium ion concentration and the C3b concentration. Factor D is about ten-fold more effective on a molar basis, for the alternative pathway C3 convertase activation than is kallikrein. The physiological role of the action of kallikrein on the alternative pathway C3 convertase is discussed.
D002499:Centrifugation, Density Gradient; D002850:Chromatography, Gel; D003166:Complement Activating Enzymes / Q000378:metabolism*; D003167:Complement Activation / Q000187:drug effects*; D050577:Complement C3-C5 Convertases / Q000378:metabolism*; D011415:Complement Factor B / Q000378:metabolism; D011416:Complement Factor D / Q000494:pharmacology; D003170:Complement Pathway, Alternative / Q000187:drug effects*; D004591:Electrophoresis, Polyacrylamide Gel; D004789:Enzyme Activation / Q000187:drug effects; D006801:Humans; D007610:Kallikreins / Q000037:antagonists & inhibitors / Q000097:blood / Q000494:pharmacology*
D003166:Complement Activating Enzymes; D050577:Complement C3-C5 Convertases; D007610:Kallikreins; C493488:CFD protein, human; D011416:Complement Factor D; D011415:Complement Factor B