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