title: Histatin 1 resists proteolytic degradation when adsorbed to hydroxyapatite.
abstract: Histatins are salivary proteins that exhibit a high affinity for hydroxyapatite and contribute to the acquired enamel pellicle. Previous studies have observed that, despite the high proteolytic activity in saliva, significant numbers of histatin molecules in acquired enamel pellicle are intact. Our working hypothesis was that histatins are less susceptible to proteinases present in saliva when adsorbed on the hydroxyapatite. To test this premise, we incubated histatin 1 with hydroxyapatite and human whole saliva. Proteolytic products of this incubation were then characterized by PAGE, HPLC, and mass spectrometry. This study shows for the first time that binding to hydroxyapatite confers intact histatin 1 with resistance to proteolytic degradation.
authors.affiliation: School of Dentistry, Dental Sciences Building-DSB0071, Schulich School of Medicine & Dentistry, The University of Western Ontario, London N6A 5C1, ON, Canada.
authors.forename: E E
authors.initials: EE
authors.lastname: McDonald
authors.forename: H A
authors.initials: HA
authors.lastname: Goldberg
authors.forename: N
authors.initials: N
authors.lastname: Tabbara
authors.forename: F M
authors.initials: FM
authors.lastname: Mendes
authors.forename: W L
authors.initials: WL
authors.lastname: Siqueira
mesh_terms: D000327:Adsorption; D000328:Adult; D000704:Analysis of Variance; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D003743:Dental Enamel / Q000378:metabolism*; D044622:Dental Pellicle / Q000378:metabolism*; D017886:Durapatite / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel / Q000379:methods; D005260:Female; D006461:Hemolysis; D054808:Histatins / Q000378:metabolism*; D006801:Humans; D008297:Male; D013058:Mass Spectrometry; D010446:Peptide Fragments / Q000032:analysis; D011485:Protein Binding; D055815:Young Adult
chemical_list: D054808:Histatins; D010446:Peptide Fragments; C068074:HTN1 protein, human; D017886:Durapatite