The effect of end-group substitution on surface self-assembly of peptides

Biofouling, the undesirable accumulation of organisms onto surfaces, affects many areas including health, water, and energy. We previously designed a tripeptide that self-assembles into a coating that prevents biofouling. The peptide comprises three amino acids: DOPA, which allows its adhesion to the surface, and two fluorinated phenylalanine residues that direct its self-assembly into a coating and acquire it with antifouling properties. This short peptide has an ester group at its C-terminus. To examine the importance of this end group for the self-assembly and antifouling properties of the peptide, we synthesized and characterized tripeptides with different end groups (ester, amide, or carboxylic group). Our results indicate that different groups at the C-terminus of the peptide can lead to a change in the peptide assembly on the surface and its adsorption process. However, this change only affects the antifouling properties of the coating toward Gram-positive bacteria (Staphylococcus epidermidis), whereas Gram-negative bacteria (Escherichia coli) are not affected.