June 9, 2005
Journal Article

A REDOR NMR Study of a Phosphorylated Statherin Fragment Bound to Hydroxyapatite Crystals

Abstract

Acidic proteins found in mineralized tissues act as nature’s crystal engineers, where they play a key role in promoting or inhibiting the growth of minerals such as hydroxyapatite (HAP), Ca10(PO4)6- (OH)2, the main mineral component of bone and teeth. There is remarkably little known about the protein structure-function relationships and the recognition processes governing hard tissue engineering. It is well-known that several salivary proteins (statherin) and peptides (SN-15, N-terminal 15 amino fragment of statherin) bind strongly to HAP to regulate crystal growth.1 In this work, we describe how solid-state NMR can be used to identify which amino acid side chains of SN-15 (DpSpSEE15NKFLRRIGRFG) interact with the HAP surface, even in the presence of phosphorylated side chains. Prior structural studies have indicated that the second through twelfth amino acids are R-helical in full length statherin on HAP, while the SN-15 fragment is in an extended structure toward the N-terminus, only gaining R-helical structure at the seventh amino acid. Additionally, prior dynamics studies have indicated that the region from the seventh amino acid to the C-terminus interacts less strongly with the HAP surface than the first six amino acids.

Revised: August 9, 2006 | Published: June 9, 2005

Citation

Gibson J.M., V. Raghunathan, J.M. Popham, P. Stayton, and G.P. Drobny. 2005. A REDOR NMR Study of a Phosphorylated Statherin Fragment Bound to Hydroxyapatite Crystals. Journal of the American Chemical Society 127, no. 26:9350-9351. doi:10.1021/ja050910m