Use of modified double-reciprocal plot for enzyme kinetic parameters. A pitfall.

The modified double-reciprocal plot suggested by Lee and Wilson (Lee, H.J. and Wilson, I.B. (1971) Biochim. Biophys. Acta 242, 519--522) has until now been accepted as giving a simple and accurate method for the determination of enzyme kinetic parameters V and Km, which can be used with little error even when as much as 50% of the substrate is consumed. In this paper it has been shown with analytical proof that the errors in the application of their method can in fact be much higher and that the integrated Michaelis-Menten equation should be used in its complete form.