COMPLEMENT SYSTEM IN A SIMPLE WAY скачать в хорошем качестве

COMPLEMENT SYSTEM IN A SIMPLE WAY

Classical pathway-It is activated by Antigen-Antibody complexes. The classical pathway consists of 4 proteins C1, C2, C3 and C4.It waits for IgM OR IgG. • C1 is a complex made of hexamer C1q and serine proteases C1r and C1s. • C1q binds to Fc region of antibody. • Activated C1s cleaves C4 and C4b either binds to antigen-antibody complex. • C1s also cleaves C2 and the C4bC2a complex is the C3 convertase of classical pathway. • Once C3b is formed – it can either follow alternative pathway or bind to C4bC2a (C3 convertase) to form C5 convertase. • Similarly, MAC is formed. Lectin pathway- The lectin pathway consists of MBL, C2, C3, C4 and some calcium-dependent lectin family proteins.MASPI and MASP2 bind to MBL which activates c4 and c2. Then it goes in the case way as in classical pathway. Alternate pathway-C3 hydrolysis in blood plasma occur.Factor b and Factor D binds and form the convertase ----MAComplex-----cell lysis.