A REDOR NMR study of a phosphorylated statherin fragment bound to hydroxyapatite crystals

J Am Chem Soc. 2005 Jul 6;127(26):9350-1. doi: 10.1021/ja050910m.

Abstract

Hydroxyapatite (HAP) is the main mineral component of teeth. It is well-known that several salivary proteins and peptides bind strongly to HAP to regulate crystal growth. Interactions between a peptide derived from the N-terminal fragment of the salivary protein statherin and HAP were measured utilizing rotational-echo double-resonance (REDOR) nuclear magnetic resonance (NMR). The REDOR measurement from the side chain of the salivary peptide to the HAP surface is complicated by two effects: a possible additional dipolar coupling to a phosphorylated side chain and the potential proximity of phosphorus atoms to each other, resulting in a homonuclear dipolar interaction. Both of these effects were addressed, and the smallest model applicable to our system includes the nitrogen-15 (15N) spin in the lysine side chain and two phosphorus-31 (31P) spins, at least one of which must be from the surface phosphates of the HAP.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Crystallization
  • Durapatite / chemistry*
  • Fluoresceins / chemistry*
  • Magnetic Resonance Spectroscopy / methods
  • Models, Statistical
  • Ouabain / analogs & derivatives*
  • Ouabain / chemistry
  • Phosphorylation
  • Salivary Proteins and Peptides / chemistry*
  • Salivary Proteins and Peptides / metabolism
  • Time Factors

Substances

  • Fluoresceins
  • STATH protein, human
  • Salivary Proteins and Peptides
  • rhodol green-ethylenediamine-ouabain
  • Ouabain
  • Durapatite