Bioactive peptides: solid state, solution and molecular dynamics studies of Cyclolinopeptide A-related cystinyl cyclopentapeptide

The conformational analysis of the disulphide cyclopentapeptide related Cyclolinopeptide A has been carried out by solid state methods using X-ray diffraction techniques, in solution by NMR, CD, IR spectroscopies and by molecular dynamic simulation analisis. The structure of the monoclinic form, presents two transannular H bonds and an intramolecular H bond between the C=O of urethane group and The Phe4 NH. MD studies carried out in vacuo shows that the structure determined by crystal state represents a energy minimum. All H bond found in solid state are correctly reproduced in vacuo and in solution simulations.