Azaproline as a beta-turn-inducer residue opposed to proline.
Azaproline (AzPro) is an analogue of proline containing a nitrogen atom in place of the C(alpha)H group. AzPro has been introduced in various model peptides, and especially in the Boc-Ala-AzPro-Ala-NHiPr tripeptide. The structural consequence of that modification has been investigated in solution by using IR and 1H NMR, with reference to the cognate proline-containing peptide. Contrary to proline, which induces beta-folding of the Pro-Ala sequence, azaproline apparently favors betaVI-folding of the Ala-AzPro one with high occurrence. Opening of the AzPro pyrazolidine ring to get N-methylazaalanine fundamentally does not change the structural properties of the azatripeptide, but allows the existence of open conformers to an extent depending on the solvent.
LCPM, CNRS-URA-494, ENSIC-INPL, Nancy, France.
M
M
Zouikri
A
A
Vicherat
A
A
Aubry
M
M
Marraud
G
G
Boussard
D001372:Aza Compounds / Q000737:chemistry*; D004121:Dimethyl Sulfoxide / Q000494:pharmacology; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008968:Molecular Conformation; D015394:Molecular Structure; D010455:Peptides / Q000737:chemistry*; D011392:Proline / Q000031:analogs & derivatives*; D017510:Protein Folding; D017433:Protein Structure, Secondary; D013237:Stereoisomerism
D001372:Aza Compounds; D010455:Peptides; D011392:Proline; D004121:Dimethyl Sulfoxide