Department of Oral Biology and Experimental Dental Research, Faculty of Dentistry, University of Szeged, Szeged, Hungary.
EKLH-SZTE Biomimetic Systems Research Group, Eötvös Loránd Research Network (ELKH), University of Szeged, Szeged, Hungary.
PLoS One. 2023 Sep 5;18(9):e0289467. doi: 10.1371/journal.pone.0289467. eCollection 2023.
The adhesion of biomolecules to dental and orthopedic implants is a fundamental step in the process of osseointegration. Short peptide motifs, such as RGD or KRSR, carried by extracellular matrix proteins or coated onto implant surfaces, accelerate cell adhesion and tissue formation. For this reason, understanding the binding mechanisms of adhesive peptides to oxidized surfaces of titanium implants is of paramount importance. We performed molecular dynamics simulations to compare the adhesion properties of 6 peptides, including the tripeptide RGD, its variants KGD and LGD, as well as the tetrapeptide KRSR, its variant LRSR and its truncated version RSR, on anatase, rutile, and amorphous titanium dioxide (TiO2) surfaces. The migration of these molecules from the water phase to the surface was simulated in an aqueous environment. Based on these simulations, we calculated the residence time of each peptide bound to the three different TiO2 structures. It was found that the presence of an N-terminal lysine or arginine amino acid residue resulted in more efficient surface binding. A pulling simulation was performed to detach the adhered molecules. The maximum pulling force and the binding energy were determined from the results of these simulations. The tri- and tetrapeptides had slightly greater adhesion affinity to the amorphous and anatase structure than to rutile in general, however specific surface and peptide binding characters could be detected. The binding energies obtained from our simulations allowed us to rank the adhesion strengths of the studied peptides.
生物分子在牙齿和骨科植入物上的黏附是骨整合过程中的一个基本步骤。细胞外基质蛋白携带的短肽基序（如 RGD 或 KRSR）或涂覆在植入物表面上，可加速细胞黏附和组织形成。因此，了解黏附肽与钛植入物氧化表面的结合机制至关重要。我们进行了分子动力学模拟，以比较 6 种肽的黏附特性，包括三肽 RGD、其变体 KGD 和 LGD，以及四肽 KRSR、其变体 LRSR 和其截短形式 RSR，在锐钛矿、金红石和无定形二氧化钛（TiO2）表面上的特性。在水相环境中模拟了这些分子从水相到表面的迁移。基于这些模拟，我们计算了每个肽结合到三种不同 TiO2 结构的停留时间。结果表明，N 端赖氨酸或精氨酸氨基酸残基的存在导致更有效的表面结合。进行了一个拉拔模拟以分离附着的分子。从这些模拟的结果中确定了最大的拉力和结合能。三肽和四肽通常对无定形和锐钛矿结构的黏附亲和力略高于金红石，但可以检测到特定的表面和肽结合特性。我们的模拟得到的结合能使我们能够对所研究的肽的黏附强度进行排序。
