Beta sheets with a twist: the conformation of helical polyisocyanopeptides determined by using vibrational circular dichroism.
Detailed information on the architecture of polyisocyanopeptides based on vibrational circular dichroism (VCD) spectroscopy in combination with DFT calculations is presented. It is demonstrated that the screw sense of the helical polyisocyanides can be determined directly from the C=N-stretch vibrational region of the VCD spectrum. Analysis of the VCD signals associated with the amide I and amide II modes provides detailed information on the peptide side-chain arrangement in the polymer and indicates the presence of a helical β-sheet architecture, in which the dihedral angles are slightly different to those of natural β-sheet helices.
Radboud University Nijmegen, Institute for Molecules and Materials, Toernooiveld 1, 6525ED Nijmegen (The Netherlands).
Erik
E
Schwartz
Vincent
V
Liégeois
Matthieu
M
Koepf
Pavol
P
Bodis
Jeroen J L M
JJ
Cornelissen
Patrick
P
Brocorens
David
D
Beljonne
Roeland J M
RJ
Nolte
Alan E
AE
Rowan
Sander
S
Woutersen
Benoît
B
Champagne
D002942:Circular Dichroism; D004151:Dipeptides / Q000737:chemistry*; D008968:Molecular Conformation; D009570:Nitriles / Q000737:chemistry*; D010455:Peptides / Q000737:chemistry*; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D011789:Quantum Theory; D013057:Spectrum Analysis; D014732:Vibration
D004151:Dipeptides; D009570:Nitriles; D010455:Peptides; C509662:poly(isocyanodipeptide)
density functional calculations; helical structures; hydrogen bonding; polyisocyanides; vibrational circular dichroism