Parole chiave: Crystal Structure, Mathematical Models, Molecular Structure, Synthesis (chemical), Beta-Alanine, Cyclotetrapeptides, Molecular Dynamics Simulation, Polypeptides, Acetonitrile, Beta Alanine, Dichloromethane, Article, Conformation, Cyclization, Energy, Nonhuman, Peptide Synthesis, Priority Journal, Purification, X Ray Analysis, Amino Acid Sequence, Molecular Sequence Data, Oligopeptides, Protein Conformation, Support, Non-U.S. Gov, Non-U. S. Gov, Hydrogen, Solvents, Water, Dicyclohexylcarbodiimide, Methylenechloride, Pentapeptide, Beta Amino Acid, Cyclopeptide, Amino Terminal Sequence, Carboxy Terminal Sequence, Hydrogen Bond, Peptide Analysis, Protein Purification, X Ray Crystallography, Comparative Study, Molecular Conformation, Chemistry,
Res. Ctr Bioactive Peptides, CEINGE, University Federico II, Via Mezzocannone 4, 80134 Napoli, Italy Department of Chemistry, Universita Federico II, Via Mezzocannone, 4, 80134 Napoli, Italy Research Center on Bioactive Peptides, CEINGE, University Federico II, Napoli, Italy.,
In the present paper we describe the synthesis, purification, and single crystal x-ray analysis of the cyclic pentapeptide cyclo-(L-Pro-L-Pro-L-Phe- β-Ala-β-Ala). The peptide was synthesized by classical solution methods and the cyclization of the free pentapeptide was accomplished in good yields in diluted methylenechloride solution using N,N-dicyclohexylcarbodiimide. The compound crystallizes in the monoclinic space group P21 from hot water with five solvent molecules. The Pro1-Pro2 peptide bond is cis and the molecular conformation is stabilized by an intramolecular hydrogen bond between the CO group of the β-Ala5 and the NH of the Phe3 residue. The Pro1-Pro2 segment occupies the relative positions 2 and 3 of a type VIa β-turn, while the L-phenylalanyl-β-alanyl-β-alanine segment is incorporated in a C13- like ring structure. The crystal packing is characterized by a network of 11 intermolecular hydrogen bonds involving all the remaining CO, NH, and the water molecules.
358 Records (352 escludendo Abstract e Conferenze). Impact factor totale: 1424.178 (1404.052 escludendo Abstract e Conferenze). Impact factor a 5 anni totale: 1475.571 (1454.565 escludendo Abstract e Conferenze).