enzyme catalysis

Glucose-6-Phosphate Appears to be a Competitive Inhibitor of the Bovine Intestine Enzyme Alkaline Phosphatase Abstract This study focuses on the effects of glucose-6-phosphate (G6P) on the kinetics of the enzyme alkaline phosphatase. Because G6P is a common molecule and has a phosphoester bond, it may prevent alkaline phosphatase from hydrolyzing certain substrates. The data collected in this study seem to indicate that G6P is a competitive inhibitor of the enzyme …

…x-intercept = -1/Km Without G6P: y=0.7505x+17.563 y intercept = 17.563 x intercept = -17.563/0.7505 Vmax = 1/17.563 = -23.27 = 0.0573 umole/min Km = -1/-23.27 = 0.043 mM With G6P: y=1.5121x+15.979 y intercept = 15.979 x intercept = -15.979/1.5121 Vmax = 1/15.979 = -10.57 = 0.0626 umole/min Km = -1/-10.57 = 0.095 mM Determining Ki x intercept = -1/ ((1+I/Ki)*Km) where x intercept is from graph with G6P, I = concentration of inhibitor, and Km is without G6P -10.57= -1/((1+0.1/Ki)*0.043) (1+0.1/Ki)*-0.454=-1 1+0.1/Ki = 2.20 0.1/Ki = 1.20 Ki = 0.083