Detection of binding reactions using labels detected by mediated catalytic electrochemistry

Abstract

A method of detecting binding interactions and target molecules, such as proteins, protein fragments, recombinant proteins, recombinant protein fragments, extracellular matrix proteins, ligands, carbohydrates, steroids, hormones, drugs, drug candidates, immunoglobulins and receptors of eukaryotic, prokaryotic or viral origin, by mediated electrochemistry using labels that react with transition metal mediator complexes in a detectable catalytic redox reaction. These labels are attached directly to binders, target molecules, surrogate target molecules, or to affinity ligands capable of binding to the target or to surrogate target molecules capable of competing with the target for binding to another binder. The labels can be naturally present (endogenous) in the binder, target or affinity ligand, or constructed by the covalent attachment of the label to the binder, target, affinity ligand or surrogate target (exogenous).

1 - 112 . (Canceled)  
     
     
         113 . A labeled member of a binding pair useful for mediated catalytic electrochemistry, comprising: 
 a) a binder selected from the group consisting of proteins, protein fragments, recombinant proteins, recombinant protein fragments, extracellular matrix proteins, ligands, carbohydrates, steroids, hormones, drugs, drug candidates, immunoglobulins, receptors of eukaryotic, prokaryotic or viral origin, and oligonucleotides; and    b) an exogenous peptide label containing one or more modified amino acids capable of being oxidized in an oxidation-reduction reaction at potentials below those of naturally occurring amino acids.    
     
     
         114 . The labeled member of a binding pair of  claim 113 , wherein the binder is an antibody.  
     
     
         115 . The labeled member of a binding pair of  claim 113 , wherein there are at least two modified amino acids in the peptide label.  
     
     
         116 . The labeled member of a binding pair of  claim 113 , wherein the modified amino acids in the peptide label are selected from the group consisting of derivatives of tyrosine and derivatives of tryptophan.  
     
     
         117 . The labeled member of a binding pair of  claim 116 , wherein the modified amino acids in the peptide label are selected from the group consisting of 5-hydroxytryptophan; 3-aminotyrosine; and 3,4-dihydroxyphenylalanine.