Patent ID: 7183392

Claim:
A heterofunctional crosslinking reagent having the formula: wherein L 1 and L 2 are each independently selected from the group consisting of a bond, a substituted or unsubstituted (C 2 –C 24 ) alkylene group, a substituted or unsubstituted (C 2 –C 24 ) heteroallcylene group, a polyethyleneglycol group, a polyalcohol group, a polyamine group, a poiyester group and a polyphosphodiester group; -L 3 -Z is an optionally protected amino acid side chain having a pendant reactive group, wherein said amino acid is selected from the group consisting of lysine, cysteine, serine, aspartic acid, glutamic acid, and threonine; X is a non-covalent protein tag binder that specifically binds to a protein tag portion of a protein; and Y is a photoactivatable covalent crosslinking group adapted to covalently link the heterofunctional crosslinking reagent at or adjacent to said protein tag, said photoactivatable covalent crosslinking group is a member selected from the group consisting of aryl ketones, azides, diazo compounds, diazirenes, and ketenes.