Preferred solution conformation of peptides rich in the lipophilic, chiral, C(alpha)-methylated alpha-amino acid (alpha Me)Aoc.
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.
Peggion
C
C
Biopolymer Research Centre, CNR, Department of Organic Chemistry, University of Padova, Italy.
Formaggio
F
F
Crisma
M
M
Toniolo
C
C
Kaptein
B
B
Broxterman
Q B
QB
Kamphuis
J
J
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
D000596:Amino Acids; D008055:Lipids; D010455:Peptides; D012996:Solutions