Calculate the Ki for a competitive inhibitor I form the foll

Calculate the Ki for a competitive inhibitor (I) form the following data.

Slope of reciprocal plot

(Km app/Vmax)                      Inhibitor Concentration (

Solution

For competitive inhibitor , the lineweaver -burk equation becomes 1/v = (Km/Vmax)(1/[S])(1 + [I]/Ki) + (1/Vmax) --------------- (a) Slope = (Km/Vmax)(1 + [I]/Ki) From the given values when [I] = 0 ,slope =0.1 therefore (Km/Vmax)=0.1 And from another value [I] = 50 micromolar = 50 x 10^-6 M the slope is 1. therefore, putting in the equation (a) we get the following equation (0.1)(1 + 50 x 10^-6/Ki) = 1 Ki = 5.55 x 10^-6 M