title: Stimuli-responsive self-assembling peptides made from antibacterial peptides.
abstract: How to use bioactive peptide sequences as fundamental building blocks to make hydrogel materials which are stimuli-responsive? In this article, we provide a novel designed peptide comprising two antibacterial peptide sequences (KIGAKI)3-NH2 and a central tetrapeptide linker. Results show that balancing the forces of the electrostatic repulsion of the charged lysine residues against the hydrophobic collapse of the isoleucine and alanine residues and backbone β-sheet hydrogen bonding allows the structural transition and formation of individually dispersed nanofibers. Circular Dichroism (CD) and rheology analysis demonstrated that the designed peptide can undergo an abrupt structural transition from a random coil to a stable unimolecular β-hairpin conformation and subsequently form an elastic hydrogel when exposed to external stimuli such as pH, ionic strength and heat. The assembly kinetics of the obtained antibacterial sequence comprising peptide (ASCP) was studied by time-lapse Atomic Force Microscopy (AFM) and Thioflavin T (ThT) binding assay. In addition, the inherent antibacterial activity of the peptide hydrogel was confirmed by the antibacterial assay against Escherichia coli. This example described epitomizes the use of bioactive peptide sequences in the design of finite self-assembled structures with potential inherent activity. These hydrogel materials may find applications in drug delivery, tissue engineering and regenerative medicine.
authors.affiliation: West China Hospital Nanomedicine Laboratory, West China Hospital, Sichuan University, Chengdu, 610041, China.
authors.forename: Yanfei
authors.initials: Y
authors.lastname: Liu
authors.forename: Yanlian
authors.initials: Y
authors.lastname: Yang
authors.forename: Chen
authors.initials: C
authors.lastname: Wang
authors.forename: Xiaojun
authors.initials: X
authors.lastname: Zhao
mesh_terms: D000595:Amino Acid Sequence; D023181:Antimicrobial Cationic Peptides / Q000737:chemistry* / Q000494:pharmacology; D002942:Circular Dichroism; D004337:Drug Carriers / Q000737:chemistry; D004926:Escherichia coli / Q000187:drug effects; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D057139:Nanofibers; D017433:Protein Structure, Secondary; D044968:Regenerative Medicine; D013696:Temperature; D023822:Tissue Engineering
chemical_list: D023181:Antimicrobial Cationic Peptides; D004337:Drug Carriers; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate