Photoaffinity labelling - A method of protein study

Photoaffinity labelling is one of the most powerful chemical modification t echniques employed in the study of protein architecture and interactions. T his approach utilises photolabile derivatives of ligands (substrates), term ed photoaffinity probes, for a covalent labelling of target proteins (enzym es). Upon UV-light photolysis, photoaffinity probes are converted to highly reactive intermediates which al e able to modify amino acid residues of a target protein. The goal of this technique is the identification of the pro be binding site(s) in a probe-protein covalent complex. In this review, maj or concepts of photoaffinity labelling are described with respect to select ion criteria of appropriate photoaffinity probes and assessment of advantag es and disadvantages of currently used photolabile probes. In addition, sev eral examples of photoaffinity probe application in protein research focuse d on the cytochrome P450 active centre are presented.