Amino acid specificity of glycation and protein−AGE crosslinking reactivities determined with a dipeptide SPOT library
Gerald Münch1, Dorothee Schicktanz1, Andrea Behme1, Manfred Gerlach2, Peter Riederer2, Dieter Palm1
& Reinhard Schinzel1
1
Department of Physiological Chemistry I, University of Würzburg, Würzburg, Germany.
2
Department of Clinical Neurochemistry, Psychiatric Hospital, University of Würzburg, Germany.
Correspondence should be addressed to Gerald Münch muench@biozentrum.uni-wuerzburg.deadvanced glycation end productsprotein crosslinkingpeptide library
Advanced glycation end products (AGEs) contribute to changes in protein conformation, loss of function, and irreversible crosslinking. Using a library of dipeptides on cellulose membranes (SPOT library), we have developed an approach to systematically assay the relative reactivities of amino acid side chains and the N-terminal amino group to sugars and protein−AGEs. The sugars react preferentially with cysteine or tryptophan when both the -amino group and the side chains are free. In peptides with blocked N-terminus and free side chains, cysteine, lysine, and histidine were preferred. Crosslinking of protein−AGEs to dipeptides with free side chains and blocked N termini occurred preferentially to arginine and tryptophan. Dipeptide SPOT libraries are excellent tools for comparing individual reactivities of amino acids for nonenzymatic modifications, and could be extended to other chemically reactive molecules.
-amino group and the side chains are free. In peptides with blocked N-terminus and free side chains, cysteine, lysine, and histidine were preferred. Crosslinking of protein−AGEs to dipeptides with free side chains and blocked N termini occurred preferentially to arginine and tryptophan. Dipeptide SPOT libraries are excellent tools for comparing individual reactivities of amino acids for nonenzymatic modifications, and could be extended to other chemically reactive molecules.
