Hydroxyapatite growth inhibition by osteopontin hexapeptide sequences
| Autor: | J S Ishal, Nasim Tishbi, C Reitblat, L D Silverman, E Leiderman, B Recca, M Saadia, I Kuyunov, R. Viswanathan |
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| Rok vydání: | 2010 |
| Předmět: |
Models
Molecular Kinetics chemistry.chemical_element Peptide Calcium chemistry.chemical_compound Adsorption Calcification Physiologic Desorption Electrochemistry Animals Humans General Materials Science Phosphorylation Spectroscopy chemistry.chemical_classification Chemistry Surfaces and Interfaces Hydrogen-Ion Concentration Condensed Matter Physics Phosphate Peptide Fragments Durapatite Biochemistry Osteopontin Absorption (chemistry) Growth inhibition Nuclear chemistry |
| Zdroj: | Langmuir : the ACS journal of surfaces and colloids. 26(12) |
| ISSN: | 1520-5827 |
| Popis: | The effects of three acidic hexapeptides on in vitro hydroxyapatite growth were characterized by pH-stat kinetic studies, adsorption isotherms, and molecular modeling. The three peptides, pSDEpSDE, SDESDE, and DDDDDD, are equal-length model compounds for the acidic sequences in osteopontin, a protein that inhibits mineral formation in both calcified and noncalcified tissues. Growth rates from 1.67 mM calcium and 1.00 mM phosphate solution were measured at pH 7.4 and 37 degrees C in 150 mM NaCl. pSDEpSDE was a strong growth inhibitor when preadsorbed onto hydroxyapatite (HA) seeds from > or = 0.67 mM solutions, concentrations where adsorption isotherms showed relatively complete surface coverage. The nonphosphorylated SDESDE control showed no growth inhibition. Although it adsorbed to almost the same extent as pSDEpSDE, it rapidly desorbed under the pH-stat growth conditions while pSDEpSDE did not. DDDDDD exhibited weak inhibition as its concentration was increased and similar adsorption/desorption behavior to pSDEpSDE. Molecular modeling yielded binding energy trends based on simple adsorption of peptides on the [100] surface that were consistent with observed inhibition, but not for the [001] surface. The relatively unfavorable binding energies for peptides on the [001] surface suggest that their absorption will be primarily on the [100] face. The kinetic and adsorption data are consistent with phosphorylation of osteopontin acting to control mineral formation. |
| Databáze: | OpenAIRE |
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