For years, mussel-inspired adhesive research has focused heavily on DOPA, the catechol-bearing amino acid long thought to be the central ingredient behind underwater sticking power. A new study from Nature Communications adds a different player to the story: a histidine-rich protein called mefp-12 that seems to help organize and cure mussel glue after secretion.
Using biochemical localization, the team found mefp-12 in vesicles of the mussel’s glue-producing glands. Sequence modeling suggested that the protein can adopt a zinc-stabilized coiled-coil structure and may contain regions with zinc-finger-like features, hinting that metal coordination could be important for its function.
In lab tests, a histidine-rich peptide derived from mefp-12 behaved in a strikingly dynamic way. In the presence of zinc and under the right pH conditions, it underwent liquid-liquid phase separation, forming fluid condensates that could merge and spread across a surface. When the environment shifted to seawater-like pH, those droplets reorganized into solid, nanoporous networks resembling the cured structure of native mussel glue.
The findings suggest that mussel adhesion is not simply a DOPA-driven phenomenon. Instead, adhesive performance may depend on a coordinated system in which histidine-rich domains, zinc binding, pH changes, and protein self-assembly work together to convert a secreted fluid into a resilient underwater material.
For bio-inspired materials research, the implication is important: future synthetic wet adhesives may need to mimic not just chemical stickiness, but also the controlled phase behavior and curing pathways that mussels use to build their glues.
