Synthesis and Wettability Characteristics of Model Adhesive Protein Sequences Inspired by a Marine Mussel

Abstract

Three adhesive polyoctapeptides (X/Y-Gly-Tyr-Ser-Ala-Gly-Tyr-Lys)n (X, Thr and Ala: Y, Thr:Ala = 3:2), which are the C-terminal octapeptide sequences shared by all those consensus motifs of a ribbed mussel Geukensia demissa adhesive protein (RMAP), have been synthesized by the polycondensation of the active esters. The correlation between wettability and adhesion with the alternative substitution by hydrophobic Ala and hydrophilic Thr in the synthetic RMAPs in aqueous solution and as films on high and low surface free energy (sfe) surfaces has been investigated by surface chemical approaches. The side chain moieties of RMAPs arrange their local conformation to adapt to the inherent surface character, and they orientate on high and low sfe surfaces. On a high sfe glass the hydrophilic side chains of the RMAP molecules face toward the surface, and on a low sfe polyethylene (HDPE) the hydrophobic side chains face toward the surface. The bonding strengths of synthetic RMAPs on glass and HDPE with and without enzymatic oxidation have been examined. Increased starting concentration exhibited the strongest adhesive capability (7.5 kgf/cm2) on alumina due to the increased cohesion among RMAP molecules. As another factor to increase adhesive ability, the intermolecular cross-linking among RMAP molecules by tyrosinase increases their adhesive capability by about 20% on HDPE, glass, and alumina except iron.

Gecko‐Inspired Surfaces: A Path to Strong and Reversible Dry Adhesives

“…by a variety of interactions such as metal coordination bonds, p-electron interactions, covalent bonds, coordination bonds, or mixed hydrophobic/hydrophilic interactions. [128,129] Fibrillar patterns coated with the adhesive polymer showed dramatic increase (up to 23-fold) in adhesion forces in wet conditions over noncoated control samples (Fig. 15).…”

Adhesive strength and curing rate of marine mussel protein extracts on porcine small intestinal submucosa

“…The potential of these proteins was first investigated by Waite et al [22,23]. Research during the past three decades has increased the scientific community's understanding of the adhesive's molecular composition and structure, and inspired many simpler synthetic analogs [24][25][26][27][28][29][30][31][32][33][34][35][36][37]. However, only a few investigators have studied the use of this exotic adhesive for surgical applications.…”

Synthesis and Surface Chemical Properties of Adhesive Protein of the Asian Freshwater Mussel,Limnoperna fortunei

“…There were two reasons for synthesizing the polydecapeptide: (i) the simple decapeptide repeating polymer was expected to be a good model for understanding the surface chemical role of the repetitive unit of Lffp, and (ii) the decapeptide sequence is a challenging target for a series of our investigations on the synthesis of adhesive proteins, as the decapeptide sequence has a variety of side chain functional groups, including acidic (Asp, Glu), basic (Lys), amide (Gln), phenolic (Tyr), and hydroxylated (Thr, Ser) residues, as compared with those of the marine adhesive proteins which contain Tyr, Lys, simple hydrophobic (Ala, Pro, Gly), and hydroxylated residues. [22,31,34,35] The synthetic route is represented in Scheme 1, and the polydecapeptide was successfully synthesized by the fragment-coupling methods designed for selective deprotection of side chain (OBzl) and C-terminus carboxyl (OMe and OEt) protecting groups, followed by the polycondensation and the two-step deprotection of the side chain protecting groups. The difficulty in assembling the Gln residue into the polypeptides was solved using the Mbh group [30] for the amide protection of the Gln residue.…”