gramicidins การใช้

• Gramicidin and alamethicin had been popular starting points for selective modifications.
• Her dissertation was on the structure of the antibiotic gramicidin.
• The antibiotics gramicidin and tyrocidine were first isolated from it.
• Gramicidin D is a linear pentadecapeptide made up of 15 amino acids.
• This is in contrast to gramicidin S, which is a cyclic peptide chain.
• X and Y depend upon the gramicidin molecule.
• See also Gramicidin A, a peptide that forms a dimeric transmembrane ?-helix.
• One peptide of gramicidin, with attached antibody, is mobile and one is fixed.
• Gramicidin D contains linear pentadecapeptides, that is chains made up of 15 amino acids.
• It is synthesized by gramicidin S synthetase.
• The 11th amino acid in these chains leads to the three different types of gramicidins.
• Thus, ions moving through the gramicidin pore carry along a single file of water molecules.
• This channel shows discrete conductance but different ion selectivity than wild type gramicidin in voltage-clamp experiments.
• In earlier work with Rene J . Dubos, Hotchkiss helped to develop two antibiotics, gramicidin and tyrocidine.
• There exist valine and isoleucine variants of all three gramicidin species, and'X'can be either.
• Y determines which is which; as Y gramicidin A contains tryptophan, B phenylalanine, and C tyrosine.
• Like valinomycin and nonactin, the gramicidin channel is selective for potassium over sodium, but only slightly so.
• It has also been noted that the amino acids that are in Gramicidin B are solely hydrophobic amino acids.
• That gramicidin D functions as a channel was demonstrated by Hladky and Haydon, who investigated the unitary conductance of the channel.
• Gramicidin B makes up 6 % of Gramicidin D while Gramicidin A and C make up 80 % and 14 % respectively.