Luo Muzhong, Gao Yuan, Yang Shengjiang, Quan Xuebo, Sun Delin, Liang Kunneng, Li Jiyao, Zhou Jian
Guangdong Provincial Key Lab for Green Chemical Product Technology, School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou, Guangdong 510640, People's Republic of China.
Phys Chem Chem Phys. 2019 May 8;21(18):9342-9351. doi: 10.1039/c9cp01638d.
Statherin is a 43 amino acid long protein, which plays an important role in the process of biomineralization of enamel. In this work, we investigated the solvent effect on the adsorption of a peptide from the N-terminus of statherin, SN15, and its mutants SNA15 and SNS15 on the (001) face of hydroxyapatite [Ca10(PO4)6(OH)2, or HAP] with molecular dynamics simulations. The simulation results showed that the adsorption of the three peptides onto the HAP(001) surface was primarily driven by salt-bridge and electrostatic attraction in calcium phosphate (Ca/P) and sodium chloride (NaCl) solutions, respectively. SN15 adsorbs on the HAP surface with the strongest electrostatic interaction, while SNS15 is the weakest. Besides, Ca2+ around SN15 can form an equilateral triangle, which resembles the structure formed by Ca(2) ions in the HAP(001) crystal face, and this looks like the initial stage of HAP nucleation. The conformational changes of SN15 on HAP are analyzed by the root-mean-square deviation. It shows that SN15 is more stable in Ca/P solution while SNS15 is more stable in NaCl solution; the stability of SNA15 is almost the same in both solutions. This work reveals the adsorption mechanism of a series of SN peptides on the HAP surface and provides guidelines for the design of biomaterials for restoring etched enamel and regulating biomineralization.
牙本质磷蛋白是一种由43个氨基酸组成的蛋白质，在牙釉质生物矿化过程中发挥着重要作用。在本研究中，我们通过分子动力学模拟研究了溶剂对牙本质磷蛋白N端的一种肽SN15及其突变体SNA15和SNS15在羟基磷灰石[Ca10(PO4)6(OH)2，简称HAP] (001)面上吸附的影响。模拟结果表明，在磷酸钙（Ca/P）和氯化钠（NaCl）溶液中，这三种肽在HAP(001)表面的吸附分别主要由盐桥和静电引力驱动。SN15以最强的静电相互作用吸附在HAP表面，而SNS15最弱。此外，SN15周围的Ca2+可形成等边三角形，类似于HAP(001)晶面中Ca(2)离子形成的结构，这看起来像是HAP成核的初始阶段。通过均方根偏差分析了SN15在HAP上的构象变化。结果表明，SN15在Ca/P溶液中更稳定，而SNS15在NaCl溶液中更稳定；SNA15在两种溶液中的稳定性几乎相同。本研究揭示了一系列SN肽在HAP表面的吸附机制，为修复蚀刻牙釉质和调节生物矿化的生物材料设计提供了指导。
