title: The backbone and side chain conformations of the cyclic tetrapeptide HC-toxin.
abstract: A study of the conformational parameters of HC-toxin and its diacetyl derivative in chloroform solution has been carried out. Two-dimensional NMR spectroscopy and the nuclear Overhauser effect have been used in order to determine connectivities (assignments and sequence) and approximate torsion angles and interproton distances. The results are consistent with a bis-gamma-turn conformation previously reported for dihydrochlamydocin. Model building based upon NMR data supports a D configuration for Ala2 and Pro4 residues.
mesh_terms: D009682:Magnetic Resonance Spectroscopy; D008433:Mathematics; D010456:Peptides, Cyclic; D011487:Protein Conformation; D014118:Toxins, Biological
chemical_list: D010456:Peptides, Cyclic; D014118:Toxins, Biological; C037654:HC toxin