The longest, regular polypeptide 3(10) helix at atomic resolution.
A synthetic, terminally blocked homodecapeptide from the C alpha, alpha-dimethylated glycyl residue alpha-aminoisobutyric acid has been analyzed by single-crystal X-ray diffraction and the structure refined to R = 0.073. The compound crystallizes as a perfect 3(10) helix, stabilized by eight consecutive intramolecular N-H . . . O = C hydrogen bonds. This is the first observation at atomic resolution of a regular polypeptide 3(10) helix as long as three complete turns.
Pavone
V
V
Department of Chemistry, University of Naples, Italy.
Di Blasio
B
B
Santini
A
A
Benedetti
E
E
Pedone
C
C
Toniolo
C
C
Crisma
M
M
D000621:Aminoisobutyric Acids; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D006860:Hydrogen Bonding; D015394:Molecular Structure; D009842:Oligopeptides; D011487:Protein Conformation; D014961:X-Ray Diffraction
D000621:Aminoisobutyric Acids; D009842:Oligopeptides; C100049:2-aminoisobutyric acid