Revealing the interaction mechanism of peptide with specific platinum facets by stochastic tunneling-basin hopping method

Abstract

This study uses the stochastic tunneling- basin hopping (STUN-BH) method to determine the most stable configurations for the peptides S7 (Ac-Ser-Ser-Phe-Pro-Gln-Pro-Asn-CONH2) and T7 (Ac-Thr-Leu-Thr-Thr-Leu-Thr-Asn-CONH2) on both Pt(1 1 1) and Pt(1 0 0) surfaces. The Amber99sb-ILDN force field was used for S7 and T7, and the TIP3P water model was used for the water environment. The CHARMM-METAL force field was adopted to model the S7 and T7 interactions with Pt(1 1 1) and Pt(1 0 0). The simulation results show that the lock-and-key (LAK) matches of both six-membered and five-membered rings of S7 on Pt(1 1 1) cause a more stable adsorption of S7 on Pt(1 1 1) than on Pt(1 0 0). For T7, the STUN-BH simulation results for multiple T7 molecules on Pt(1 1 1) and Pt(1 0 0) show the configurations of T7 molecules on Pt(1 0 0) are relatively more extended than those on Pt(1 1 1). Moreover, the order parameter of T7 molecules on Pt(1 0 0) is higher than that of T7 molecules on Pt(1 1 1), indicating that it is relatively easier for the T7 molecules to form a complete T7 layer on Pt(1 0 0) than on Pt(1 1 1).