title: Preferred solution conformation of peptides rich in the lipophilic, chiral, C(alpha)-methylated alpha-amino acid (alpha Me)Aoc.
abstract: The lipophilic, chiral, C(alpha)-methylated alpha-amino acid L-(alphaMe)Aoc (2-methyl-2-amino-octanoic acid) was prepared using a chemo-enzymatic approach. Two series of terminally protected model peptides, from dimer through to hexamer, containing L-(alphaMe)Aoc in combination with either Gly or Aib, were synthesized by solution methods and were fully characterized. A solution conformational analysis, based on FT-IR absorption, 1H-NMR and circular dichroism (CD) techniques, was performed with the aim at determining the preferred conformation of this novel amino acid and the relationship between chirality at its alpha-carbon atom and screw sense of the helix that is formed. The results obtained strongly support the view that L-(alphaMe)Aoc favours the formation of the right-handed 3(10)-helical conformation.
authors.affiliation: Biopolymer Research Centre, CNR, Department of Organic Chemistry, University of Padova, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Peggion
authors.forename: F
authors.initials: F
authors.lastname: Formaggio
authors.forename: M
authors.initials: M
authors.lastname: Crisma
authors.forename: C
authors.initials: C
authors.lastname: Toniolo
authors.forename: B
authors.initials: B
authors.lastname: Kaptein
authors.forename: Q B
authors.initials: QB
authors.lastname: Broxterman
authors.forename: J
authors.initials: J
authors.lastname: Kamphuis
mesh_terms: D000596:Amino Acids / Q000032:analysis* / Q000737:chemistry; D002942:Circular Dichroism; D008055:Lipids / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D008745:Methylation; D010455:Peptides / Q000737:chemistry*; D011487:Protein Conformation; D012996:Solutions; D017550:Spectroscopy, Fourier Transform Infrared; D013237:Stereoisomerism
chemical_list: D000596:Amino Acids; D008055:Lipids; D010455:Peptides; D012996:Solutions