Development of a Multifunctional Antimicrobial Peptide for Marine Antifouling by Theoretical Calculations and Experimental Approaches

Marine biofouling poses significant challenges to the economy, safety, and reliability of marine infrastructure. While antimicrobial peptides (AMPs) have emerged as green and efficient antifouling agents, their single functionality and the complexity of preparing antifouling surfaces remain key challenges. This study introduces a multifunctional AMP with combined adhesion and antimicrobial properties, derived from 3,4-dihydroxy-l-phenylalanine (DOPA) and IP12 (sequence IRLRWRWKWPWP). The directional recombination of AMP was guided by theoretical calculations. Density functional theory (DFT) simulations identify that the hydroxyl groups of DOPA were the main activating groups that react with aluminum alloy. Coarse-grained molecular dynamics (CG MD) and all-atom molecular dynamics (AA MD) simulations revealed that amino acid residues near the N-terminal of the IP12 could induce cell membrane bending and rupture. The AMP surfaces were fabricated to validate the accurate calibration of the simulations and performance of multifunctional AMP. Atomic force microscopy, Fourier transform infrared, and X-ray photoelectron spectroscopy results confirm the successful construction of AMP surfaces through adhesion function. Antifouling evaluations demonstrated the antifouling properties of AMP surfaces against Escherichia coli (Gram-negative) and Bacillus sp. (Gram-positive), achieving antifouling rates of 85.8 and 82.4%, respectively. This study provides valuable insights into the design of multifunctional AMPs.