title: Temporal and compositional characteristics of salivary protein adsorption to hydroxyapatite.
abstract: Salivary proteins bind to enamel surfaces and hydroxyapatite in a highly selective manner. Numerous studies have identified these proteins as primarily proline-rich proteins, cystatins, statherin, and histatins. Previously, the hydroxyapatite-binding potential of these proteins had been characterized in systems consisting of singly purified protein and adsorbent. The purpose of this study was to investigate the adsorption of each protein in the presence of complete salivary secretion. Proteins, shown to adsorb to hydroxyapatite, were purified, biotinylated, and added back to the remaining proteins to form a series of reconstituted secretions. The adsorption of each biotinylated protein in the reconstituted secretion to hydroxyapatite was then measured as a function of time. Results indicated that three different adsorption patterns occur. A simple hyperbolic pattern is characteristic of amylase, glycosylated proline-rich protein (PRG), and cystatin. A faster adsorption process is observed for PRP-3, PRP-4, PIF-f, and statherin. A more complex pattern, exhibiting a rapid phase followed by a slower phase, is characteristic of PRP-1, PRP-2, PIF-s, and histatins. These results suggest that there are different adsorption processes involved in the binding of salivary proteins to hydroxyapatite. Two possible mechanisms are direct adsorption of protein to hydroxyapatite and indirect adsorption of protein by interacting with other proteins already bound to hydroxyapatite.
authors.affiliation: Department of Periodontology and Oral Biology, Boston University Medical Center, Massachusetts 02118, USA.
authors.forename: M S
authors.initials: MS
authors.lastname: Lamkin
authors.forename: A A
authors.initials: AA
authors.lastname: Arancillo
authors.forename: F G
authors.initials: FG
authors.lastname: Oppenheim
mesh_terms: D000327:Adsorption; D000681:Amylases / Q000032:analysis / Q000737:chemistry; D002135:Calcium-Binding Proteins / Q000032:analysis / Q000737:chemistry; D002850:Chromatography, Gel; D015891:Cystatins / Q000032:analysis / Q000737:chemistry; D015853:Cysteine Proteinase Inhibitors / Q000032:analysis / Q000737:chemistry; D003741:Dental Deposits / Q000737:chemistry; D003743:Dental Enamel; D017886:Durapatite / Q000737:chemistry*; D006023:Glycoproteins / Q000032:analysis / Q000737:chemistry; D006801:Humans; D010306:Parotid Gland / Q000378:metabolism; D010455:Peptides / Q000032:analysis / Q000737:chemistry; D010750:Phosphoproteins / Q000032:analysis / Q000737:chemistry; D011392:Proline / Q000032:analysis / Q000737:chemistry; D055232:Proline-Rich Protein Domains; D011485:Protein Binding; D011506:Proteins / Q000032:analysis / Q000737:chemistry; D012463:Saliva / Q000378:metabolism; D055273:Salivary Proline-Rich Proteins; D012471:Salivary Proteins and Peptides / Q000032:analysis / Q000737:chemistry*; D013363:Submandibular Gland / Q000378:metabolism; D013997:Time Factors; D000099053:Histidine-Rich Glycoprotein
chemical_list: D002135:Calcium-Binding Proteins; D015891:Cystatins; D015853:Cysteine Proteinase Inhibitors; D006023:Glycoproteins; C524536:PRH1 protein, human; D010455:Peptides; D010750:Phosphoproteins; D011506:Proteins; C018149:STATH protein, human; D055273:Salivary Proline-Rich Proteins; D012471:Salivary Proteins and Peptides; D000099053:Histidine-Rich Glycoprotein; D017886:Durapatite; D011392:Proline; D000681:Amylases