... for each concentration of the inhibitor by nonlinear fit of the data from the abovenegative controls; [I] is the concentration of the inhibitor,IC50is the concentration of inhibitor that causes ... 7.4. Then, proteolysis was started by the addition of 50 lLof10mgÆmL)1a-casein. At different time-points,60 lL aliquots were withdrawn and the reaction wasstopped by the addition of 60 lLof1.8Mtrichloroaceticacid. ... þS½EC50bð4Þwhere [S] is the concentration of the sample, EC50is the effective concentration that causes 50% of the effect, andb represents the cooperativity of the effect.HemagglutinationHamster,...