Trapping a folding intermediate of the alpha-helix: stabilization of the pi-helix.
We report the design, synthesis, and characterization of a short peptide trapped in a pi-helix configuration. This high-energy conformation was nucleated by a preorganized pi-turn, which was obtained by replacing an N-terminal intramolecular main chain i and i + 5 hydrogen bond with a carbon-carbon bond. Our studies highlight the nucleation parameter as a key factor contributing to the relative instability of the pi-helix and allow us to estimate fundamental helix-coil transition parameters for this conformation.
Chapman
Ross
R
Department of Chemistry, New York University, New York, New York 10003, USA.
Kulp
John L
JL
Patgiri
Anupam
A
Kallenbach
Neville R
NR
Bracken
Clay
C
Arora
Paramjit S
PS
D000595:Amino Acid Sequence; D002942:Circular Dichroism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D019906:Nuclear Magnetic Resonance, Biomolecular; D010455:Peptides / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism; D017510:Protein Folding; D017433:Protein Structure, Secondary
D010455:Peptides