Using peptide arrays created by the SPOT method for defining protein-protein interactions

Evaluating sites of protein-protein interactions can be an arduous task involving extensive mutagenesis work and attempts to express and purify individual proteins in sufficient quantities. Peptide mapping is a useful alternative to traditional methods as it allows rapid detection of regions and/or individual residues important for binding, and it can be readily applied to numerous proteins at once. Here we describe the use of the ResPep SL SPOT method to evaluate protein–protein binding interactions such as that between Gproteinβγsubunits and SNARE proteins, identifying both regions of interest and subsequently individual residues which can then be manipulated in further biochemical assays to confirm their validity.