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Toward Artificial Mussel-Glue Proteins: Differentiating Sequence Modules for Adhesion and Switchable Cohesion |
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| Authors: | Dr. Sandra Arias Dr. Shahrouz Amini Dr. Justus Horsch Matthias Pretzler Prof. Annette Rompel Inga Melnyk Dmitrii Sychev Prof. Andreas Fery Prof. Hans G. Börner |
| Affiliation: | 1. Laboratory for Organic Synthesis of Functional Systems Department of Chemistry, Humboldt-Universität zu Berlin, Brook-Taylor-Straße 2, 12489 Berlin, Germany;2. Max Planck Institute of Colloids and Interfaces, Department of Biomaterials, 14424 Potsdam, Germany;3. Universität Wien, Fakultät für Chemie Institut für Biophysikalische Chemie, Althanstraße 14, 1090 Wien, Austria;4. Leibniz-Institut für Polymerforschung Dresden e.V. Institute of Physical Chemistry and Polymer Physics, Hohe Straße 6, 01069 Dresden, Germany;5. Leibniz-Institut für Polymerforschung Dresden e.V. Institute of Physical Chemistry and Polymer Physics, Hohe Straße 6, 01069 Dresden, Germany Technische Universität Dresden, Chair of Physical Chemistry of Polymeric Materials, Hohe Straße 6, 01069 Dresden, Germany |
| Abstract: | Artificial mussel-glue proteins with pH-triggered cohesion control were synthesized by extending the tyrosinase activated polymerization of peptides to sequences with specific modules for cohesion control. The high propensity of these sequence sections to adopt β-sheets is suppressed by switch defects. This allows enzymatic activation and polymerization to proceed undisturbed. The β-sheet formation is regained after polymerization by changing the pH from 5.5 to 6.8, thereby triggering O→N acyl transfer rearrangements that activate the cohesion mechanism. The resulting artificial mussel glue proteins exhibit rapid adsorption on alumina surfaces. The coatings resist harsh hypersaline conditions, and reach remarkable adhesive energies of 2.64 mJ m−2 on silica at pH 6.8. In in situ switch experiments, the minor pH change increases the adhesive properties of a coating by 300 % and nanoindentation confirms the cohesion mechanism to improve bulk stiffness by around 200 %. |
| Keywords: | adhesion cohesion control enzyme-induced polymerization mussel glue synthetic proteins |