Inhibition of human C3 convertase assessed as inhibition of C3a and C3b fragment production at pH 7.4 after 30 mins by SDS-PAGE using 7% (w/v) polyacrylamide gel
Inhibition of human C3 convertase assessed as inhibition of C3a and C3b fragment production at pH 7.4 after 30 mins by SDS-PAGE using 12% (w/v) polyacrylamide gel
Biological Assay: Recombinant human factor B (expressed in drosophila cells and purified using standard methods) labeled with biotin (10 nM), europium-labeled streptavidin (5 nM) and (+) or (−)-2-((1E,3E,5E)-5-(1-(6-((2-(3-(4-((R)-3-amino-3-phenylpropanoyl)-1-(4-amino-6,7-dimethoxyquinazolin-2-yl)piperazin-2-yl)phenoxy)ethyl)amino)-6-oxohexyl)-3,3-dimethyl-5-sulfoindolin-2-ylidene)penta-1,3-dien-1-yl)-1-ethyl-3,3-dimethyl-5-sulfo-3H-indol-1-ium (Biological Example 2.6, 240 nM activity against factor B when tested using the assay of Biological Example 1) (75 nM) were incubated with test compound at various concentrations up to 2 hours at room temperature in 20 mM Tris/HCl, pH 7.4, 0.005% (v/v) Tween20.The time-gated decrease in fluorescence intensity related to the competition between labeled and unlabeled factor B ligands was recorded at both 620 nm and 665 nm, 70 μs after excitation at 337 nm using a microplate spectrofluorimeter.