A REDOR NMR study of a phosphorylated statherin fragment bound to hydroxyapatite crystals.
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.
Department of Bioengineering, University of Washington, Seattle, Washington 98195, USA.
James M
JM
Gibson
Vinodhkumar
V
Raghunathan
Jennifer M
JM
Popham
Patrick S
PS
Stayton
Gary P
GP
Drobny
D003460:Crystallization; D017886:Durapatite / Q000737:chemistry*; D005452:Fluoresceins / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D015233:Models, Statistical; D010042:Ouabain / Q000031:analogs & derivatives* / Q000737:chemistry; D010766:Phosphorylation; D012471:Salivary Proteins and Peptides / Q000737:chemistry* / Q000378:metabolism; D013997:Time Factors
D005452:Fluoresceins; C018149:STATH protein, human; D012471:Salivary Proteins and Peptides; C109049:rhodol green-ethylenediamine-ouabain; D010042:Ouabain; D017886:Durapatite