title: Concentration of salivary protective proteins within the bound oral mucosal pellicle.
abstract: OBJECTIVE
  To study which salivary proteins form the protective bound mucosal pellicle and to determine the role of transglutaminase in pellicle development.
  
  
  METHODS
  Oral epithelial cells were collected and underwent washes of different strengths, followed by homogenisation. SDS-PAGE, western blotting, IgA ELISAs and amylase activity assays were completed on cell homogenates and compared to saliva samples to confirm which salivary proteins were bound to cell surfaces.
  
  
  RESULTS
  Salivary mucins, MUC5B and MUC7, were strongly retained on the oral epithelial cell surface. Other bound proteins including cystatin S, carbonic anhydrase VI, secretory component and IgA could be washed off. IgA was present in concentrated levels in the bound mucosal pellicle compared to amounts in saliva. Amylase, one of the most abundant proteins present in saliva, showed minimal levels of binding. Transglutaminase 3 presence was confirmed, but proteins that it catalyses cross-links between, statherin and proline-rich proteins, showed minimal presence.
  
  
  CONCLUSIONS
  Some protective salivary proteins including mucins and IgA become concentrated on oral surfaces in the bound mucosal pellicle, through specific interactions. Concentration of mucins would contribute to lubrication to prevent abrasion damage to soft tissues, whilst increased IgA could create an 'immune reservoir' against mucosal infection.
authors.affiliation: Salivary Research Unit, King's College London Dental Institute, London, UK.
authors.forename: H L
authors.initials: HL
authors.lastname: Gibbins
authors.forename: G B
authors.initials: GB
authors.lastname: Proctor
authors.forename: G E
authors.initials: GE
authors.lastname: Yakubov
authors.forename: S
authors.initials: S
authors.lastname: Wilson
authors.forename: G H
authors.initials: GH
authors.lastname: Carpenter
mesh_terms: D002473:Cell Wall; D044622:Dental Pellicle / Q000737:chemistry*; D006801:Humans; D009061:Mouth Mucosa / Q000737:chemistry*; D055257:Mucin-5B / Q000032:analysis*; D009077:Mucins / Q000032:analysis*; D012471:Salivary Proteins and Peptides / Q000032:analysis*
chemical_list: C524578:MUC5B protein, human; C083238:MUC7 protein, human; D055257:Mucin-5B; D009077:Mucins; D012471:Salivary Proteins and Peptides
keywords: IgA; mucins; pellicle; proteins; saliva