Specific binding assay with an enzyme modulator as a labeling substance

Abstract

A specific binding assay method employing, as a labeling substance, a reversibly binding enzyme modulator for the detection of a ligand in a liquid medium. The method follows conventional specific binding assay techniques of either the homogeneous or heterogeneous type wherein the liquid medium to be assayed is combined with reagent means that includes a labeled conjugate to form a binding reaction system having a bound-species and a free-species of the conjugate. The amount of conjugate resulting in the bound-species or the free-species is a function of the amount of ligand present in the liquid medium assayed. In the present invention, the labeled conjugate comprises a reversibly binding enzyme modulator covalently linked to a binding component of the binding reaction system. The distribution of the conjugate between the bound-species and the free-species is determined by addition of an enzyme whose activity is affected, either decreased or increased, by said modulator and measuring the resulting activity of the enzyme. The enzyme modulator may be a conventional enzyme inhibitor, preferably of the coompetitive type, or an allosteric effector.

Dependencies are inferred from the claim text.