title: Reactivity of human salivary proteins families toward food polyphenols.
abstract: Tannins are well-known food polyphenols that interact with proteins, namely, salivary proteins. This interaction is an important factor in relation to their bioavailability and is considered the basis of several important properties of tannins, namely, the development of astringency. It has been generally accepted that astringency is due to the tannin-induced complexation and/or precipitation of salivary proline-rich proteins (PRPs) in the oral cavity. However, this complexation is thought to provide protection against dietary tannins. Neverthless, there is no concrete evidence and agreement about which PRP families (acidic, basic, and glycosylated) are responsible for the interaction with condensed tannins. In the present work, human saliva was isolated, and the proteins existing in saliva were characterized by chromatographic and proteomic approaches (HPLC-DAD, ESI-MS, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and MALDI-TOF). These approaches were also adapted to study the affinity of the different families of salivary proteins to condensed tannins by the interaction of saliva with grape seed procyanidins. The results obtained when all the main families of salivary proteins are present in a competitive assay, like in the oral cavity, demonstrate that condensed tannins interact first with acidic PRPs and statherin and thereafter with histatins, glycosylated PRPs, and bPRPs.
authors.affiliation: Chemistry Investigation Center (CIQ), Department of Chemistry, Faculty of Sciences, University of Porto, Porto, Portugal.
authors.forename: Susana
authors.initials: S
authors.lastname: Soares
authors.forename: Rui
authors.initials: R
authors.lastname: Vitorino
authors.forename: Hugo
authors.initials: H
authors.lastname: Osório
authors.forename: Ana
authors.initials: A
authors.lastname: Fernandes
authors.forename: Armando
authors.initials: A
authors.lastname: Venâncio
authors.forename: Nuno
authors.initials: N
authors.lastname: Mateus
authors.forename: Francisco
authors.initials: F
authors.lastname: Amado
authors.forename: Victor
authors.initials: V
authors.lastname: de Freitas
mesh_terms: D005419:Flavonoids / Q000737:chemistry*; D005502:Food; D006801:Humans; D010636:Phenols / Q000737:chemistry*; D059808:Polyphenols; D044945:Proanthocyanidins / Q000737:chemistry; D055232:Proline-Rich Protein Domains; D012471:Salivary Proteins and Peptides / Q000737:chemistry*; D012639:Seeds / Q000737:chemistry; D013634:Tannins / Q000737:chemistry; D027843:Vitis
chemical_list: D005419:Flavonoids; D010636:Phenols; D059808:Polyphenols; D044945:Proanthocyanidins; D012471:Salivary Proteins and Peptides; D013634:Tannins