Calorimetric study of inhibition of urease by 2-mercaptoethanol Procedures based upon integrated rate equations

Urease-catalyzed hydrolysis of urea was studied in the absence, and presence, of 0.3 and 0.8 mmol dm⁻³ 2-mercaptoethanol in phosphate buffer at pH 7.0 at 25°C with the use of an isoperibol calorimeter. The extent of reaction with time, ΔT vs. t, was interpreted with the help of the integrated Michaelis–Menten equation, and the inhibition constant K_i was obtained from linear transformations of the equation (Jennings–Niemann, Yun–Suelter and Booman–Niemann). The obtained value of K_i was equal to 0.87±0.10 mmol dm⁻³.