Probing the Natural-Abundance¹³C Populations of Insoluble Elastin Using¹³C−¹H Heteronuclear Correlation (HETCOR) NMR Spectroscopy

The complexities of fibrous proteins in their native states often preclude the use of high-resolution solid-state NMR spectroscopy, particularly those utilizing multiple dimensions. In this Study, the application of solid-state C-13-H-1 heteronuclear correlation spectroscopy with frequency-switched Lee-Goldburg decoupling (FSLG-HETCOR) to an unenriched sample of native elastin is reported. These 2D experiments on lyophilized and hydrated elastin illustrate that individual contributions to the overall profile in the aliphatic region of its C-13 spectrum may be resolved. As a result, details of side-chain packing in the hydrated and dehydrated elastin are elucidated. Generally, the HETCOR data show that the removal of water produces a compact state in this protein.