1 research outputs found
Althusser and the Critique of Political Economy
Two disulfide-containing peptides,
barrettides A (<b>1</b>) and B (<b>2</b>), from the cold-water
marine sponge <i>Geodia barretti</i> are described. Those
31 amino acid residue
long peptides were sequenced using mass spectrometry methods and structurally
characterized using NMR spectroscopy. The structure of <b>1</b> was confirmed by total synthesis using the solid-phase peptide synthesis
approach that was developed. The two peptides were found to differ
only at a single position in their sequence. The three-dimensional
structure of <b>1</b> revealed that these peptides possess a
unique fold consisting of a long β-hairpin structure that is
cross-braced by two disulfide bonds in a ladder-like arrangement.
The peptides are amphipathic in nature with the hydrophobic and charged residues clustered on separate
faces of the molecule. The barrettides were found not to inhibit the
growth of either <i>Escherichia coli</i> or <i>Staphylococcus
aureus</i> but displayed antifouling activity against barnacle
larvae (<i>Balanus improvisus</i>) without lethal effects
in the concentrations tested