The Bolton and Hunter Method for Radiolabeling Protein

Abstract

This is an indirect method in which an acylating reagent (N-succinimidyl-3[4-hydroxyphenyl]propionate, the Bolton and Hunter reagent), commercially available in a radioiodinated form, is covalently coupled to the protein to be labeled (1). The [¹²⁵I] Bolton and Hunter reagent reacts mostly with the side-chain amino groups of lysine residues to produce the labeled protein. It is the method of choice for radiolabeling proteins that lack tyrosine and histidine residues, or where reaction at those residues affects biological activity. It is particularly suitable for proteins that are sensitive to the oxidative procedures employed in other methods (see Chapters 132, 133, and 135).