). In all cases, the maleimide constraint was found to have a limited or negative impact on the inhibitory potency of the peptide. However, we found that some positions were more tolerant to modification than others, with constrained peptides N-Myc61-89-L82C/E86C-mal, N-Myc61-89-E80C/E84C-mal and N-Myc61-89-T79C/L83C-mal showing only minor loss in potency when compared to the native peptide.