Phase-dependent redox insulation in mussel adhesion

Abstract

Catecholic 3,4-dihydroxyphenyl-l-alanine (Dopa) residues in mussel foot proteins (mfps) contribute critically to mussel (Mytilus californianus) plaque adhesion, but only if protected from oxidation at the adhesive-substratum interface. Dopa oxidation is thermodynamically favorable in seawater yet barely detectable in plaques; therefore, we investigated how plaques insulate Dopa-containing mfps against oxidation. Seawater sulfate triggers an mfp3 and mfp6 liquid-liquid phase separation (LLPS). By combining plaque cyclic voltammetry with electrophoresis, mass spectrometry, and redox-exchange chemistry, we show that Dopa-containing mfp3 and mfp6 in phase-separated droplets remain stable despite rapid oxidation in the surrounding equilibrium solution. The results suggest that a cohort of oxidation-prone proteins is endowed with phase-dependent redox stability. Moreover, in forming LLPS compartments, Dopa proteins become reservoirs of chemical energy.

Genetically Engineered Polypeptide Adhesive Coacervates for Surgical Applications

“…[35,37] We speculate that the robust adhesion performance of K-NAT glues might be related to the presence of strong π-π stacking and cation-π interactions. [13,29,30,38] We also investigated photo-modulation of the adhesion performance by switching the azobenzene moiety from trans-to cis configuration. However, it turned out that the light irradiation with different wavelength didn't change the adhesion performance of the K-NAT adhesive.…”

Omics‐based molecular analyses of adhesion by aquatic invertebrates

“…It may also be that the data required to further our understanding of mussel adhesion cannot be derived from 'omics studies (see e.g. Valois, Mirshafian & Waite, 2020). Recently, however, novel organisms for the study of bioadhesion have been selected for their existing 'omics resources and not for more practical reasons as was the case for barnacles and mussels (both of which are problematic biofouling organisms).…”

From vesicles to materials: bioinspired strategies for fabricating hierarchically structured soft matter

“…Waite and co-workers have established the role of at least seven proteins in the plaque adhesive known as mussel foot proteins (mfp), which have different numbers based on their order of discovery (e.g. mfp-2, mfp-3, etc) [5,29]. Notably, many of these proteins are enriched with 3,4-dihydroxyphenylalanine (DOPA)—a post-translational modification of the amino acid tyrosine (figure 1 c ).…”