Molecular mechanics of mussel adhesion proteins
Molecular mechanics of mussel adhesion proteins
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DOI：
10.1016/j.jmps.2013.08.015
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发表时间：
2014
影响因子：
5.3
通讯作者：
Zhao Qin;M. Buehler
中科院分区：
文献类型：
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作者：
Zhao Qin;M. Buehler
贻贝足蛋白（mfp）是一种由海洋贻贝产生的天然胶，是一种有趣的材料，因为它在各种环境中具有优越的粘附能力。例如，非常少量的这种材料足以将贻贝固定在水中的基底上，在波浪动力作用引起的极端力下提供结构支撑。为了更全面地了解其强度和水下可加工性，有必要了解蛋白质结构与各种底物相互作用的微观机制。然而，没有一个贻贝蛋白质的结构是已知的，这阻止了我们直接使用原子模型来探测它们的结构和机械性能。在这里，我们使用先进的分子采样技术来鉴定两种贻贝足蛋白（mfp-3和mfp-5）的分子结构，并使用这些结构来研究它们的粘附机制，然后将其纳入连续体模型。我们计算了贻贝足蛋白在二氧化硅衬底上的粘附能，并根据分子模拟结果计算了粘附强度，并与实验数据进行了比较。结果与实验结果吻合较好，验证了多尺度模型的有效性。我们发现折叠贻贝足蛋白的分子结构（最终由其基因序列定义）有利于与底物的强粘附，其中l - 3,4 -二羟基苯丙氨酸（或DOPA）蛋白亚基以合作方式增强粘附。我们的实验数据表明，峰值附着力为0.4±0.1 N，与多尺度模型F c= 0.21-0.33 N的预测结果相吻合。从这些结果中获得的原理可以指导新型界面材料（如复合材料）的制造，以有效地将有机表面与无机表面结合起来。
Mussel foot protein (mfp), a natural glue produced by marine mussel, is an intriguing material because of its superior ability for adhesion in various environments. For example, a very small amount of this material is sufficient to affix a mussel to a substrate in water, providing structural support under extreme forces caused by the dynamic effects of waves. Towards a more complete understanding of its strength and underwater workability, it is necessary to understand the microscropic mechanisms by which the protein structure interacts with various substrates. However, none of the mussel proteins’ structure is known, preventing us from directly using atomistic modeling to probe their structural and mechanical properties. Here we use an advanced molecular sampling technique to identify the molecular structures of two mussel foot proteins (mfp-3 and mfp-5) and use those structures to study their mechanics of adhesion, which is then incorporated into a continuum model. We calculate the adhesion energy of the mussel foot protein on a silica substrate, compute the adhesion strength based on results obtained from molecular modeling, and compare with experimental data. Our results show good agreement with experimental measurements, which validates the multiscale model. We find that the molecular structure of the folded mussel foot protein (ultimately defined by its genetic sequence) favors strong adhesion to substrates, where L-3, 4-dihydroxyphenylalanine (or DOPA) protein subunits work in a cooperative manner to enhance adhesion. Our experimental data suggests a peak attachment force of 0.4±0.1 N, which compares favorably with the prediction from the multiscale model of F c= 0.21–0.33 N. The principles learnt from those results could guide the fabrication of new interfacial materials (eg composites) to integrate organic with inorganic surfaces in an effective manner.