title: Peptidomic analysis of human acquired enamel pellicle.
abstract: Human acquired enamel pellicle is the result of a selective interaction of salivary proteins and peptides with the tooth surface. In the present work, the characterization of the peptides as well as the type of interactions established with the enamel surface was performed. Peptides from in vivo bovine enamel implants in the human oral cavity were sequentially extracted using guanidine and trifluoroacetic acid solutions and the fractions obtained were analysed by LC-MS and LC-MS/MS. Based on the LC-MS data, six phosphorylated peptides were identified in an intact form, strongly adsorbed to the enamel surface. Data from the LC-MS/MS analyses allowed us to identified 30 fragment peptides non-covalently bonded to enamel [basic proline-rich proteins, histatins (1 and 3) and acidic proline-rich protein classes]. The tandem mass spectrometry experiments showed the existence of a pattern of amide bond cleavage for the different identified peptide classes suggesting a selective proteolytic activity. For histatins, a predominance of cleavage at Arg, Lys and His residues was observed, while for basic proline-rich proteins, cleavage at Arg and Pro residues prevailed. In the case of acidic proline-rich proteins, a clearly predominance of cleavage of the Gln-Gly amide bond was evident.
authors.affiliation: Department of Chemistry, University of Aveiro, Aveiro, Portugal.
authors.forename: Rui
authors.initials: R
authors.lastname: Vitorino
authors.forename: Maria João
authors.initials: MJ
authors.lastname: Calheiros-Lobo
authors.forename: Jason
authors.initials: J
authors.lastname: Williams
authors.forename: António J
authors.initials: AJ
authors.lastname: Ferrer-Correia
authors.forename: Kenneth B
authors.initials: KB
authors.lastname: Tomer
authors.forename: José A
authors.initials: JA
authors.lastname: Duarte
authors.forename: Pedro M
authors.initials: PM
authors.lastname: Domingues
authors.forename: Francisco M L
authors.initials: FM
authors.lastname: Amado
mesh_terms: D000328:Adult; D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D002853:Chromatography, Liquid / Q000379:methods; D044622:Dental Pellicle / Q000737:chemistry*; D054808:Histatins / Q000032:analysis; D006801:Humans; D008297:Male; D010446:Peptide Fragments / Q000032:analysis* / Q000737:chemistry*; D010455:Peptides / Q000032:analysis / Q000737:chemistry; D055232:Proline-Rich Protein Domains; D011506:Proteins; D012463:Saliva / Q000737:chemistry*; D012471:Salivary Proteins and Peptides / Q000032:analysis* / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods; D053719:Tandem Mass Spectrometry / Q000379:methods; D000099053:Histidine-Rich Glycoprotein
chemical_list: C068075:HTN3 protein, human; D054808:Histatins; D010446:Peptide Fragments; D010455:Peptides; D011506:Proteins; D012471:Salivary Proteins and Peptides; D000099053:Histidine-Rich Glycoprotein; C068074:HTN1 protein, human