Structure of Isolated Tyrosyl-Glycyl-Glycine Tripeptide. A comparative conformational study with peptides containing an aromatic ring

”. EXEQUIEL E. BARRERA GUISASOLA, MARCELO F. MASMAN, RICARDO D. ENRIZ AND ANA M. RODRÍGUEZ

CENTRAL EUROPEAN JOURNAL OF CHEMISTRY

VERSITA

Año: 2010

1895-1066

The potential energy surface (PES) of tyrosyl-glycyl-glycine (YGG) tripeptide in solution was explored using EDMC (Electrostatically Driven Monte Carlo) and in the gas-phase by means of ab initio quantum chemical calculations. The theoretical computational analysis  revealed that this tripeptide possesses a significant molecular flexibility. A C7 backbone conformation was the most energetically  preferred for the central Gly residue, using both methodologies. Some new stable conformers that have not been previously reported sis  revealed that this tripeptide possesses a significant molecular flexibility. A C7 backbone conformation was the most energetically  preferred for the central Gly residue, using both methodologies. Some new stable conformers that have not been previously reported 7 backbone conformation was the most energetically  preferred for the central Gly residue, using both methodologies. Some new stable conformers that have not been previously reportedwere identified in the gas phase as well. This study points out the interplay of backbone and side-chain contributions in determining the relative stabilities of energy minima. In addition, the peptide backbone of YGG was compared with other small peptides containingaromatic side-chains (Phe-Gly-Gly and Trp-Gly-Gly). The comparison with experimental X-ray results was also satisfactory.sis  revealed that this tripeptide possesses a significant molecular flexibility. A C7 backbone conformation was the most energetically  preferred for the central Gly residue, using both methodologies. Some new stable conformers that have not been previously reported 7 backbone conformation was the most energetically  preferred for the central Gly residue, using both methodologies. Some new stable conformers that have not been previously reportedwere identified in the gas phase as well. This study points out the interplay of backbone and side-chain contributions in determining the relative stabilities of energy minima. In addition, the peptide backbone of YGG was compared with other small peptides containingaromatic side-chains (Phe-Gly-Gly and Trp-Gly-Gly). The comparison with experimental X-ray results was also satisfactory.