Key Laboratory for Molecular Enzymology and Engineering of Ministry of Education, School of Life Science, Jilin University, 2699 Qianjin Street, Changchun 130012, China.
Int J Mol Sci. 2021 Oct 6;22(19):10813. doi: 10.3390/ijms221910813.
Thermal stability is a limiting factor for effective application of D-psicose 3-epimerase (DPEase) enzyme. Recently, it was reported that the thermal stability of DPEase was improved by immobilizing enzymes on graphene oxide (GO) nanoparticles. However, the detailed mechanism is not known. In this study, we investigated interaction details between GO and DPEase by performing molecular dynamics (MD) simulations. The results indicated that the domain (K248 to D268) of DPEase was an important anchor for immobilizing DPEase on GO surface. Moreover, the strong interactions between DPEase and GO can prevent loop α1'-α1 and β4-α4 of DPEase from the drastic fluctuation. Since these two loops contained active site residues, the geometry of the active pocket of the enzyme remained stable at high temperature after the DPEase was immobilized by GO, which facilitated efficient catalytic activity of the enzyme. Our research provided a detailed mechanism for the interaction between GO and DPEase at the nano-biology interface.
热稳定性是 D-阿洛酮糖 3-差向异构酶（DPEase）有效应用的限制因素。最近有报道称，通过将酶固定在氧化石墨烯（GO）纳米粒子上可以提高 DPEase 的热稳定性。然而，其详细的机制尚不清楚。在这项研究中，我们通过进行分子动力学（MD）模拟来研究 GO 和 DPEase 之间的相互作用细节。结果表明，DPEase 的结构域（K248 到 D268）是将 DPEase 固定在 GO 表面上的重要锚点。此外，DPEase 和 GO 之间的强相互作用可以防止 DPEase 的环α1'-α1 和β4-α4发生剧烈波动。由于这两个环包含活性位点残基，因此在 DPEase 被 GO 固定后，酶的活性口袋的几何形状在高温下保持稳定，从而促进了酶的高效催化活性。我们的研究为 GO 和 DPEase 在纳米生物学界面的相互作用提供了详细的机制。
