title: Creation and investigation of protein-core mimetics with parallel and antiparallel aligned amino acids.
abstract: Mimetic protein cores were created that align a set of l-Phe, d-Phe, or l-Leu residues in a parallel or an antiparallel arrangement in chloroform. Not all cores show a single conformation at room temperature. Stable structures require a synergistic relationship between the H-bonding groups and the residues within the core. The spatial arrangement of the side chains dictates whether a zippered or a crossed pattern of H-bonds is observed for these cores. Variable-temperature (1)H NMR experiments were used to determine the strengths of the H-bonds. The existence of H-bonds was verified through FTIR spectroscopic analysis. Large temperature coefficients exist for some protons of aromatic rings that are held in a T-shaped arrangement. A comparison of these temperature coefficients shows that a more stable core is obtained by combining benzenoid and nitrobenzenoid rings as compared to benzenoid rings. Structures were determined using a combination of 2D NMR analysis and molecular modeling.
authors.affiliation: Department of Chemistry, University of Cincinnati, Cincinnati, OH 45221-0172, USA.
authors.forename: Juris
authors.initials: J
authors.lastname: Fotins
authors.forename: David B
authors.initials: DB
authors.lastname: Smithrud
mesh_terms: D000596:Amino Acids / Q000737:chemistry*; D006860:Hydrogen Bonding; D007930:Leucine / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D018716:Molecular Mimicry; D015394:Molecular Structure; D010649:Phenylalanine / Q000737:chemistry; D011487:Protein Conformation; D011506:Proteins / Q000138:chemical synthesis* / Q000737:chemistry*; D013816:Thermodynamics
chemical_list: D000596:Amino Acids; D011506:Proteins; D010649:Phenylalanine; D007930:Leucine