Study of Activation and Inhibition of Certain Metal Ions to Amylase Catalyzed Reaction by Microcalorimetry

With or without activation or inhibition of metal ion, the power‐time curves of amylase catalyzed reaction were determined by a 2277 thermal activity monitor (Sweden). The Michaelis constant ( K ), apparent Michaelis constant ( K m ), maximum velocity ( v m ) and apparent maximum velocity ( v am ) of amylase catalyzed reaction were obtained using thermokinetic theory and reduced extent method. On the basis of data obtained, the following relationships between K m and concentration of metal ion ( c ) were established for inhibitor of Ni 2+ K m = 2.9648 × 10 −3 ‐1.3912 × 10 −4 c R =0.9998 for inhibitor of Co 2+ K m = 1.0227 × 10 −3 + 8.2676 × 10 −6 c R = 0.9955 for activator of Ca 2+ K m = 1.0630 × 10– 7 c 2‐ 1.8311 × 10 −6 c + 9.3058 × 10 −6 R = 0.9999 for activator of Li + K m = 5.6300 × 10– 8 c 2‐ 1.5329 × 10 −6 c + 1.2662 × 10 −5 R = 0.9999 The K m ‐ c relationships show a strenuous inhibitory effect for Ni 2+ and a strenuous active effect for Ca 2+ .