Structures and Antifouling Properties of Self-assembled Zwitterionic Peptide Monolayers: Effects of Peptide Charge Distributions and Divalent Cations.
Structures and Antifouling Properties of Self-assembled Zwitterionic Peptide Monolayers: Effects of Peptide Charge Distributions and Divalent Cations.
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DOI：
10.1021/acs.biomac.0c00062
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发表时间：
2020-04
影响因子：
6.2
通讯作者：
Chuanxi Li;Chunjiang Liu;Minglun Li;Xin Xu;Shuzhou Li;W. Qi;R. Su;Jing Yu
中科院分区：
文献类型：
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作者：
Chuanxi Li;Chunjiang Liu;Minglun Li;Xin Xu;Shuzhou Li;W. Qi;R. Su;Jing Yu
两性离子肽是许多生物医学应用中防污涂层材料的绝佳候选者。我们结合表面等离子体共振（SPR）、原子力显微镜（AFM）和所有原子分子动力学（MD）模拟技术，研究了具有不同肽链长度和电荷分布的表面束缚两性离子肽单层的结构和防污性能。我们的结果表明，具有更多两性离子赖氨酸（K）和谷氨酸（E）重复单元的两性离子肽表现出更好的防污性能。肽中正电荷和负电荷的块电荷分布（在相同数量的负电荷旁边有多个正电荷）虽然影响肽分子的结构，但不会显着改变肽单层在含有单价离子的溶液中的防污性能。然而，溶液中的二价阳离子 Ca2+ 和 Mg2+ 会显着改变两性离子肽单层的结构并降低其防污性能，特别是对于块电荷序列。所有原子MD模拟定量地表明，溶液中的二价阳离子会导致肽链之间产生更多的链间静电交联，特别是对于带有块电荷的肽，这会导致两性离子肽脱水并降低其防污性能。
Zwitterionic peptides are great candidates as antifouling coating materials in many biomedical applications. We investigated the structure and antifouling properties of surface tethered zwitterionic peptide monolayers with different peptide chain lengths and charge distributions using a combination of surface plasma resonance (SPR), atomic force microscopy (AFM), and all atomistic molecular dynamics (MD) simulation techniques. Our results demonstrate that zwitterionic peptides with more zwitterionic lysine (K) and glutamic acid (E) repeating units exhibit better antifouling performance. The block charge distributions of the positive and negative charges in the peptides (having multiple positive charges next to the same amount of negative charges) although affecting the structure of the peptide molecules, do not significantly change the antifouling properties of the peptide monolayers in the solutions containing monovalent ions. However, divalent cations, Ca2+ and Mg2+, in solution can significantly alter the structure and lower the antifouling performance of the zwitterionic peptide monolayers, especially with the sequences of block charges. All atomistic MD simulations quantitatively reveal that the divalent cations in solution lead to more inter-chain electrostatic crosslinks between peptide chains, especially for peptides with block charges, which causes dehydration of the zwitterionic peptides and diminishes their antifouling performances.