Superior Antifouling Performance of a Zwitterionic Peptide Compared to an Amphiphilic, Non-Ionic Peptide

Abstract

The aim of this study was to explore the influence of amphiphilic and zwitterionic structures on the resistance of protein adsorption to peptide self-assembled monolayers (SAMs) and gain insight into the associated antifouling mechanism. Two kinds of cysteine-terminated heptapeptides were studied. One peptide had alternating hydrophobic and hydrophilic residues with an amphiphilic sequence of CYSYSYS. The other peptide (CRERERE) was zwitterionic. Both peptides were covalently attached onto gold substrates via gold-thiol bond formation. Surface plasmon resonance analysis results showed that both peptide SAMs had ultralow or low protein adsorption amounts of 1.97-11.78 ng/cm2 in the presence of single proteins. The zwitterionic peptide showed relatively higher antifouling ability with single proteins and natural complex protein media. We performed molecular dynamics simulations to understand their respective antifouling behaviors. The results indicated that strong surface hydration of peptide SAMs contributes to fouling resistance by impeding interactions with proteins. Compared to the CYSYSYS peptide, more water molecules were predicted to form hydrogen-bonding interactions with the zwitterionic CRERERE peptide, which is in agreement with the antifouling test results. These findings reveal a clear relation between peptide structures and resistance to protein adsorption, facilitating the development of novel peptide-containing antifouling materials.

Amphiphilic Polymer Platforms: Surface Engineering of Films for Marine Antibiofouling

“…This can be achieved by controlling the exact order of addition of the aminoacid building blocks and therefore the location of the hydrophilic and hydrophobic components in the peptide chain backbone. Peptide SAMs with alternating or uniformly distributed negative and positive charges, as well as amphiphilic and zwitterionic peptide SAMs were proven to be effective in limiting the adsorption of non‐specific proteins …”

“…Peptide SAMs with alternating or uniformly distributed negative and positive charges, as well as amphiphilic and zwitterionic peptide SAMs were proven to be effective in limiting the adsorption of non-specific proteins. [155,156] Novel amphiphilic oligopeptide-based systems were synthesised with a blocky or alternating distribution of the selected hydrophilic and hydrophobic aminoacids and attached to a polystyrene-b-poly(dimethylsiloxane-covinylmethylsiloxane) (PS-b-P(DMS-co-VMS)) diblock copolymer via thiol-ene click chemistry. [157] NEXAFS analysis evidenced the lack of oligopeptide at the surface and the almost exclusive presence of the lowest surface energy PDMS component, both before and after 3 d immersion in water.…”

Surface Plasmon Resonance: Material and Interface Design for Universal Accessibility

“…148–150 Ye et al recently compared the anti-fouling capabilities of two polypeptides, one of which was an amphiphilic, nonionic heptapeptide and the other was zwitterionic in nature. 146 SPR sensor surfaces were created by the self-assembly of these polypeptides onto a gold surface via interaction with N-terminal cysteine residues and were exposed to both individual proteins and complex media. It was demonstrated that, although the amphiphilic peptide SAM exhibited good antifouling properties toward single proteins, the zwitterionic peptide had an improved performance toward both single proteins and natural protein matrices, which was attributed to an increased and stable hydration layer surrounding the zwitterionic peptide.…”

Amino Acid Functional Polymers: Biomimetic Polymer Design Enabling Catalysis, Chiral Materials, and Drug Delivery

“…[80,81] Imitating these peptides with synthetic polymers is a strategy employed to synthesize better coatings and cell-penetrating materials. Locock et al and Exley et al synthesized guanidine functional polymers; [82,83] however, these were synthesized from a material other than arginine.…”