Kk. Kumashiro et al., Selection of side-chain carbons in a high-molecular-weight, hydrophobic peptide using solid-state spectral editing methods, J BIOM NMR, 18(2), 2000, pp. 139-144
Solid-state spectral editing techniques have been used by others to simplif
y C-13 CPMAS spectra of small organic molecules, synthetic organic polymers
, and coals. One approach utilizes experiments such as cross-polarization-w
ith-polarization-inversion and cross-polarization-with-depolarization to ge
nerate subspectra. This work shows that this particular methodology is also
applicable to natural-abundance C-13 CPMAS NMR studies of high-molecular-
weight biopolymers. The editing experiments are demonstrated first with mod
el peptides and then with alpha -elastin, a high-molecular-weight peptidyl
preparation obtained from the elastic fibers in mammalian tissue. The latte
r has a predominance of small, nonpolar residues, which is evident in the c
rowded aliphatic region of typical C-13 CPMAS spectra. Spectral editing is
particularly useful for simplifying the aliphatic region of the NMR spectru
m of this elastin preparation.