Photoaffinity Labelling - A Method of Protein Study

Abstract

Photoaffinity labelling is one of the most powerful chemical modification techniques employed in the study of protein architecture and interactions. This approach utilises photolabile derivatives of ligands (substrates), termed photoaffinity probes, for a covalent labelling of target proteins (enzymes). Upon UV-light photolysis, photoaffinity probes are converted to highly reactive intermediates which are able to modify amino acid residues of a target protein. The goal of this technique is the identification of the probe binding site(s) in a probe-protein covalent complex. In this review, major concepts of photoaffinity labelling are described with respect to selection criteria of appropriate photoaffinity probes and assessment of advantages and disadvantages of currently used photolabile probes. In addition, several examples of photoaffinity probe application in protein research focused on the cytochrome P450 active centre are presented.