[The method of Hill's coefficient calculation for the region of inhibition of an enzyme by excess of the substrate. Inhibition of phosphofructokinase by excess of ATP].

The new method for Hill's coefficient (nH) calculation in the region of substrate concentrations where the latter acts as an inhibitor has been developed. The method does not need preliminary determination of maximum value of enzyme reaction rate (V) for ascending branch of the plot of enzyme reaction rate versus substrate concentration and allows to avoid over-estimation of value of nH when the magnitude of optimal reaction rate is less than value of V. The literature data for inhibition of phosphofructokinase by excess of ATP are used for illustration of applicability of the suggested method of Hill's coefficient calculation.