The Effect of Calcium and Halide Ions on the Gramicidin A Molecular State and Antimicrobial Activity.

ABSTRACT: Gramicidin A (gA) forms several convertible conformations in different environments. In this study, we investigated the effect of calcium halides on the molecular state and antimicrobial activity of gramicidin A. The molecular state of gramicidin A is highly affected by the concentration of calcium salt and the type of halide anion. Gramicidin A can exist in two states that can be characterized by circular dichroism (CD), mass, nuclear magnetic resonance (NMR) and fluorescence spectroscopy. In State 1, the main molecular state of gramicidin A is as a dimer, and the addition of calcium salt can convert a mixture of four species into a single species, which is possibly a left-handed parallel double helix. In State 2, the addition of calcium halides drives gramicidin A dissociation and denatu

SUBMITTER: Carillo KD 

PROVIDER: S-EPMC7503548 | biostudies-literature | 2020 Aug

REPOSITORIES: biostudies-literature