Patent ID: 8569481

Claim:
A capture compound of formula: wherein: X is a reactivity function that covalently binds to amino acid side chains of proteins; Y, the selectivity function, interacts non-covalently with proteins and modulates one or more of the affinity, steric properties and electronic properties of the capture compound thereby increasing selectivity of the binding by X to the amino acid side chains of the proteins, whereby X covalently binds to fewer side chains of the proteins when Y is present than in its absence; Q permits separation or immobilization of the capture compound and is selected from among biotin, 6-His, an oligonucleotide, BODIPY, an adhesive peptide, and peptide nucleic acid (PNA); Z is a trityl derivative for presenting functional moieties X, Y and Q; and Z has the formula: any two of moieties Q, X and Y are attached to the phenyl rings, and the remaining moiety is attached to the central carbon atom; wherein one or more of X, Y or Q is optionally attached to a spacer moiety.