The alanine scanning strategy is the most broadly used approach to characterize individual amino acids in a peptide sequence, in regards to their contribution to their binding affinity or activity . The method is based on the systematic substitution of residues with alanine, followed then by a biological assay. The alanine residue eliminates the influence of all the side chain atoms beyond the beta-carbon atom, thus probing the role of side chain functional groups. However, the number of mutated sequences to test is limited to the number of residues in the peptide sequence. Here, a multialanine substitution strategy was used to increase the number of mutated sequences (Fig. ), thus also exploring the contribution from multiple positions to binding affinity and inferring information about relationships between residues within the sequence.