Mussels can strongly adhere to hydrophilic minerals in sea habitats by secreting adhesive proteins. The adhesion ability of these proteins is often attributed to the presence of Dopa derived from posttranslational modification of Tyr, whereas the contribution of structural feature is overlooked. It remains largely unknown how adhesive proteins overcome the surface-bound water layer to establish underwater adhesion. Here, we use molecular dynamics simulations to probe the conformations of adhesive protein Pvfp-5β and its salt-tolerant underwater adhesion on superhydrophilic mica. Dopa and positively charged basic residues form pairs, in this intrinsically disordered protein, and these residue pairs can lead to firm surface binding. Our simulations further suggest that the unmodified Tyr shows similar functions on surface adhesion by forming pairing structure with a positively charged residue. We confirm the presence of these residue pairs and verify the strong binding ability of unmodified proteins using nuclear magnetic resonance spectroscopy and lap shear tests.

贻贝可以通过分泌粘附蛋白强烈粘附在海洋生境中的亲水性矿物质上。这些蛋白质的粘附能力通常归因于来自 Tyr 的翻译后修饰的多巴的存在，而结构特征的贡献被忽略了。粘附蛋白如何克服表面结合的水层以建立水下粘附在很大程度上仍然未知。在这里，我们使用分子动力学模拟来探测粘附蛋白 Pvfp-5β 的构象及其在超亲水云母上的耐盐水下粘附。在这种本质上无序的蛋白质中，多巴和带正电的碱性残基形成对，这些残基对可以导致牢固的表面结合。我们的模拟进一步表明，未修饰的 Tyr 通过与带正电荷的残基形成配对结构，在表面粘附上显示出相似的功能。我们确认了这些残基对的存在，并使用核磁共振光谱和搭接剪切测试验证了未修饰蛋白质的强结合能力。