Premium
Exploring Helical Folding of Oligoureas During Chain Elongation by High‐Resolution Magic‐Angle‐Spinning (HRMAS) NMR Spectroscopy
Author(s) -
Violette Aude,
Lancelot Nathalie,
Poschalko Alexander,
Piotto Martial,
Briand JeanPaul,
Raya Jesus,
Elbayed Karim,
Bianco Alberto,
Guichard Gilles
Publication year - 2008
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.200701923
Subject(s) - chemistry , random hexamer , magic angle spinning , nuclear magnetic resonance spectroscopy , dimer , folding (dsp implementation) , two dimensional nuclear magnetic resonance spectroscopy , crystallography , nmr spectra database , characterization (materials science) , stereochemistry , materials science , spectral line , organic chemistry , nanotechnology , physics , astronomy , electrical engineering , engineering
The development of novel folding oligomers (foldamers) for biological and biomedical applications requires both precise structural information and appropriate methods to detect folding propensity. However, the synthesis and the systematic conformational investigation of large arrays of oligomers to determine the influence of factors, such as chain length, side chains, and surrounding environment, on secondary structure can be quite tedious. Herein, we show for 2.5‐helical N , N ′‐linked oligoureas (γ‐peptide lineage) that the whole process of foldamer characterization can be accelerated by using high‐resolution magic‐angle‐spinning (HRMAS) NMR spectroscopy. This was achieved by monitoring a simple descriptor of conformational homogeneity (e.g., chemical shift difference between diastereotopic main chain CH 2 protons) at different stages of oligourea chain growth on a solid support. HRMAS NMR experiments were conducted on two sets of oligoureas, ranging from dimer to hexamer, immobilized on DEUSS, a perdeuterated poly(oxyethylene)‐based solid support swollen in solvents of low to high polarity. One evident advantage of the method is that only minute amount of material is required. In addition, the resonance of the deuterated resin is almost negligeable. On‐bead NOESY spectra of high quality and with resolution comparable to that of liquid samples were obtained for longer oligomers, thus allowing detailed structural characterization.