Conformational Heterogeneity and Self-Assembly of ?,?,?-Hybrid Peptides Containing Fenamic Acid: Multistimuli-Responsive Phase-Selective Gelation.

ABSTRACT: The effect of fenamic acid-?-aminoisobutyric acid corner motif in ?,?,?-hybrid peptides has been reported. From X-ray single-crystal diffraction studies, it is observed that Phe-containing peptide 1 has an "S"-shaped conformation that is stabilized by two consecutive intramolecular N-H···N hydrogen bonds. However, the tyrosine analogue peptide 2 has an "S"-shaped conformation, which is stabilized by consecutive intramolecular six-member N-H···N and seven-member N-H···O hydrogen bonds. The asymmetric unit of peptide 3 containing m-aminobenzoic acid has two molecules which are stabilized by multiple intermolecular hydrogen-bonding interactions. There are also ?-? stacking interactions between the aromatic rings of fenamic acid. The peptides 1 and 2 have a polydisperse microsphere morphology, but peptide 3 has an entangled fiber-like morphology. Peptides 1-3 do not form organogels. However, in the presence of water, the peptide 3 forms a phase-selective instant gel in xylene. The gel exhibits high stability and thermal reversibility. The phase-selective gel of peptide 3 is highly responsive to H2SO4.

SUBMITTER: Chowdhury SR 

PROVIDER: S-EPMC7017408 | biostudies-literature | 2020 Feb

REPOSITORIES: biostudies-literature