Structure-activity relationship study of the plant-derived decapeptide OSIP108 inhibiting Candida albicans biofilm formation.

We performed a structure-activity relationship study of the antibiofilm plant-derived decapeptide OSIP108. Introduction of positively charged amino acids R, H, and K resulted in an up-to-5-fold-increased antibiofilm activity against Candida albicans compared to native OSIP108, whereas replacement of R9 resulted in complete abolishment of its antibiofilm activity. By combining the most promising amino acid substitutions, we found that the double-substituted OSIP108 analogue Q6R/G7K had an 8-fold-increased antibiofilm activity.