protein_function: Factor H functions as a cofactor in the inactivation ofC3b by factor I and also increases the rate of dissociation of theC3bBb complex (C3 convertase) and the (C3b)NBB complex (C5convertase) in the alternative complement pathway..
Complement factor H (CFH), originally known as beta-1H globulin, is a serum glycoprotein that regulates the function of the alternativecomplement pathway in fluid phase and on cellular surfaces. It binds to C3b, accelerates the decay of the alternative pathway convertase C3bBb, and also acts as a cofactor for complement factor I, another C3b inhibitor. The CFH gene is located on chromosome 1q32-q32.1 within a cluster of genes encoding the regulatory complement components of the activation of C3 (RCA for "regulators of complement activation"). This gene cluster includes decay-accelerating factor (DAF), C4-binding protein (C4BPA and C4BPB), and the factor H-related genes CFHR1, CFHR2, CFHR3, CFHR4, and CFHR5, among others. The gene family has arisen by multiple duplication events.