Arias Sandra, Amini Shahrouz, Horsch Justus, Pretzler Matthias, Rompel Annette, Melnyk Inga, Sychev Dmitrii, Fery Andreas, Börner Hans G
Laboratory for Organic Synthesis of Functional Systems Department of Chemistry, Humboldt-Universität zu Berlin, Brook-Taylor-Straße 2, 12489, Berlin, Germany.
Max Planck Institute of Colloids and Interfaces, Department of Biomaterials, 14424, Potsdam, Germany.
Angew Chem Int Ed Engl. 2020 Oct 12;59(42):18495-18499. doi: 10.1002/anie.202008515. Epub 2020 Aug 19.
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 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 %.
通过将酪氨酸酶激活的肽聚合扩展到具有特定内聚力控制模块的序列，合成了具有pH触发内聚力控制的人工贻贝胶蛋白。这些序列片段形成β-折叠的高倾向被开关缺陷抑制。这使得酶促活化和聚合不受干扰地进行。聚合后，通过将pH从5.5变为6.8，恢复β-折叠的形成，从而引发O→N酰基转移重排，激活内聚力机制。所得的人工贻贝胶蛋白在氧化铝表面表现出快速吸附。涂层能抵抗恶劣的高盐条件，在pH 6.8时在二氧化硅上达到2.64 mJ·m的显著粘附能。在原位开关实验中，微小的pH变化使涂层的粘附性能提高了300%，纳米压痕证实内聚力机制使整体刚度提高了约200%。
