title: Trace Solvent as a Predominant Factor To Tune Dipeptide Self-Assembly.
abstract: Solvent molecules such as water are of key importance for tuning self-assembly in biological systems. However, it remains a great challenge to detect the role of different types of noncovalent interactions between trace solvents and biomolecules such as peptides. In this work, we discover a dominant role of trace amounts of solvents for mediation of dipeptide self-assembly, in which solvent-bridged hydrogen bonding is demonstrated as a crucial force in directing fiber formation. Hydrogen-bond-forming solvents (including ethanol, N,N-dimethylformamide, and acetone) can affect the hydrogen bonding of C═O and N-H in diphenylalanine (FF) molecules with themselves, but this does not induce π-π stacking between FF molecules. The directional hydrogen bonding promotes a long-range-ordered arrangement of FF molecules, preferentially along one dimension to form nanofibers or nanobelts. Furthermore, we demonstrate that water with strong hydrogen-bond-forming capability can notably speed up structure formation with long-range order, revealing the importance of water as a trace solvent for regulation of persistent and robust fiber formation.
authors.forename: Juan
authors.initials: J
authors.lastname: Wang
authors.affiliation: University of Chinese Academy of Sciences , Beijing 100049, People's Republic of China.
authors.forename: Kai
authors.initials: K
authors.lastname: Liu
authors.forename: Linyin
authors.initials: L
authors.lastname: Yan
authors.forename: Anhe
authors.initials: A
authors.lastname: Wang
authors.forename: Shuo
authors.initials: S
authors.lastname: Bai
authors.forename: Xuehai
authors.initials: X
authors.lastname: Yan
mesh_terms: D004151:Dipeptides / Q000737:chemistry*; D000431:Ethanol / Q000737:chemistry; D006860:Hydrogen Bonding; D008752:Methylene Chloride / Q000737:chemistry; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D012997:Solvents / Q000737:chemistry
chemical_list: D004151:Dipeptides; D012997:Solvents; D000431:Ethanol; D008752:Methylene Chloride
keywords: dipeptide; fibers; hydrogen bonding; self-assembly; trace solvent