The precisely regulated, sequential interaction of proteins (in the blood) that is triggered by a complex of antibody and antigen to cause lysis of infected cells. The triggering of lysis by multivalent antibody-antigen complexes is mediated by the classical pathway, beginning with the activation of CI, the first component (protein) of the pathway. This activation step, in which CI undergoes conversion from a zymogen to an active protease, results in sequential cleavage of the C4, C2, C3, and C5 components (proteins). C5b, a fragment of C5, then joins C6, C7, and C8 to penetrate the (cell) membrane bearing the antigen. Finally, the binding of some 16 molecules of C9 to this “bridgehead” produces large pores in the (cell) membrane, which cause the lysis and destruction of the target cell.<\/p>\n
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The precisely regulated, sequential interaction of proteins (in the blood) that is triggered by a complex of antibody and antigen to cause lysis of infected cells. The triggering of lysis by multivalent antibody-antigen complexes is mediated by the classical pathway, beginning with the activation of CI, the first component (protein) of the pathway. This activation […]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3],"tags":[],"class_list":["post-37470","post","type-post","status-publish","format-standard","hentry","category-c"],"yoast_head":"\n