Solid state NMR of salivary calculi: Proline-rich salivary proteins, citrate, polysaccharides, lipids, and organic–mineral interactions

Abstract

Solid state NMR (ssNMR) can characterize mineral ( 31 P) and organic ( 13 C) components of human salivary stones ( n = 8). All show apatitic 31 P spectra. 13 C ssNMR indicates more protein, of more consistent composition, than apatitic uroliths, with prominent signals from Tyr, Phe, and His. Citrate and lipids, identified by dipolar dephasing (DD), and polysaccharides are also observable in varying amounts. 13 C{ 31 P} rotational echo double resonance ( 13 C{ 31 P} REDOR) identifies carbon atoms in close (