title: Peptide-Graphene Interactions Enhance the Mechanical Properties of Silk Fibroin.
abstract: Studies reveal that biomolecules can form intriguing molecular structures with fascinating functionalities upon interaction with graphene. Then, interesting questions arise. How does silk fibroin interact with graphene? Does such interaction lead to an enhancement in its mechanical properties? In this study, using large-scale molecular dynamics simulations, we first examine the interaction of graphene with several typical peptide structures of silk fibroin extracted from different domains of silk fibroin, including pure amorphous (P1), pure crystalline (P2), a segment from N-terminal (P3), and a combined amorphous and crystalline segment (P4), aiming to reveal their structural modifications. Our study shows that graphene can have intriguing influences on the structures formed by the peptides with sequences representing different domains of silk fibroin. In general, for protein domains with stable structure and strong intramolecular interaction (e.g., β-sheets), graphene tends to compete with the intramolecular interactions and thus weaken the interchain interaction and reduce the contents of β-sheets. For the silk domains with random or less ordered secondary structures and weak intramolecular interactions, graphene tends to enhance the stability of peptide structures; in particular, it increases the contents of helical structures. Thereafter, tensile simulations were further performed on the representative peptides to investigate how such structure modifications affect their mechanical properties. It was found that the strength and resilience of the peptides are enhanced through their interaction with graphene. The present work reveals interesting insights into the interactions between silk peptides and graphene, and contributes in the efforts to enhance the mechanical properties of silk fibroin.
authors.affiliation: Institute of High Performance Computing, A*STAR , Singapore 138632, Singapore.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Cheng
authors.affiliation: Institute of Materials Research and Engineering, A*STAR , Singapore 117602, Singapore.|Department of Biomedical Engineering, National University of Singapore , Singapore 117575, Singapore.
authors.forename: Leng-Duei
authors.initials: LD
authors.lastname: Koh
authors.affiliation: Biomechanics and Biomaterials Laboratory, Department of Applied Mechanics, Beijing Institute of Technology , Beijing 100081, China.
authors.forename: Dechang
authors.initials: D
authors.lastname: Li
authors.affiliation: Biomechanics and Biomaterials Laboratory, Department of Applied Mechanics, Beijing Institute of Technology , Beijing 100081, China.
authors.forename: Baohua
authors.initials: B
authors.lastname: Ji
authors.affiliation: School of Computing, Engineering, and Mathematics, Western Sydney University , Locked Bag 1797, Penrith NSW 2751, Australia.
authors.forename: Yingyan
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Institute of High Performance Computing, A*STAR , Singapore 138632, Singapore.
authors.forename: Jingjie
authors.initials: J
authors.lastname: Yeo
authors.affiliation: Institute of High Performance Computing, A*STAR , Singapore 138632, Singapore.|Institute of Materials Research and Engineering, A*STAR , Singapore 117602, Singapore.
authors.forename: Guijian
authors.initials: G
authors.lastname: Guan
authors.affiliation: Institute of Materials Research and Engineering, A*STAR , Singapore 117602, Singapore.|Department of Biomedical Engineering, National University of Singapore , Singapore 117575, Singapore.
authors.forename: Ming-Yong
authors.initials: MY
authors.lastname: Han
authors.affiliation: Institute of High Performance Computing, A*STAR , Singapore 138632, Singapore.
authors.forename: Yong-Wei
authors.initials: YW
authors.lastname: Zhang
mesh_terms: D001696:Biomechanical Phenomena; D005349:Fibroins / Q000737:chemistry*; D006108:Graphite / Q000737:chemistry*; D006860:Hydrogen Bonding; D056004:Molecular Dynamics Simulation; D010455:Peptides / Q000737:chemistry*
chemical_list: D010455:Peptides; D006108:Graphite; D005349:Fibroins
keywords: graphene; hydrogen bonding; mechanical property; molecular dynamics; silk fibroin; structures