RESUMO
High-resolution solid-state (13)C NMR spectra are presented for samples of alpha-elastin prepared from the aorta of normal and copper-deficient pigs. Chemical shifts of the various peaks indicate that both the normal and undercross-linked peptides have similar overall structures. However, (13)C T(1), (13)C T(1 rho), and (1)H T(1 rho) measurements indicate that the alpha-elastin peptides obtained from the abnormal elastic fibers samples exhibit altered mobilities, particularly in their side chains. Results from spectra taken with a range of contact times and from dipolar dephasing experiments are consistent with conclusions reached with the relaxation measurements. Namely, the loss of function associated with the undercross-linked sample is correlated to a small but measurable difference in relative mobility.
