Self-Assembly of Block Heterochiral Peptides into Helical Tapes. Academic Article uri icon

abstract

  • Patterned substitution of d-amino acids into the primary sequences of self-assembling peptides influences molecular-level packing and supramolecular morphology. We report that block heterochiral analogs of the model amphipathic peptide KFE8 (Ac-FKFEFKFE-NH2), composed of two FKFE repeat motifs with opposite chirality, assemble into helical tapes with dimensions greatly exceeding those of their fibrillar homochiral counterparts. At sufficient concentrations, these tapes form hydrogels with┬áreduced storage moduli but retain the shear-thinning behavior and consistent mechanical recovery of the homochiral analogs. Varying the identity of charged residues (FRFEFRFE and FRFDFRFD) produced similarly sized nonhelical tapes, while a peptide with nonenantiomeric l- and d-blocks (FKFEFRFD) formed helical tapes closely resembling those of the heterochiral KFE8 analogs. A proposed energy-minimized model suggests that a kink at the interface between l- and d-blocks leads to the assembly of flat monolayers with nonidentical surfaces that display alternating stacks of hydrophobic and charged groups.

author list (cited authors)

  • Clover, T. M., O'Neill, C. L., Appavu, R., Lokhande, G., Gaharwar, A. K., Posey, A. E., White, M. A., & Rudra, J. S.

complete list of authors

  • Clover, Tara M||O'Neill, Conor L||Appavu, Rajagopal||Lokhande, Giriraj||Gaharwar, Akhilesh K||Posey, Ammon E||White, Mark A||Rudra, Jai S

publication date

  • January 1, 2020 11:11 AM