Preparing monomeric metal ion chelator containing diacetyl glycine group linked to proteinaceous molecule

Abstract

A precursor for the construction of chelated metal conjugates which demonstrate improved assay performance and utility in minimizing non-specific binding while maintaining specificity for target molecules is disclosed. The precursor has tridentate functionality towards multivalent ions such as iron and nickel and contains a diacetyl glycine group covalently linked via an amide to a molecule such as a proteinaceous molecule providing a primary amide group for amide bond formation. The precursor is preferably prepared in monomeric form by reacting nitrilotriacetic acid or a salt thereof in an aqueous medium at an alkaline pH of at least 8 with a proteinaceous molecule containing a primary amine group in the presence of a carbodiimide. The proteinaceous molecule may be bovine serum albumin or an enzyme such as alkaline phosphatase or horseradish peroxidase.

Dependencies are inferred from the claim text.