title: Tuft protein: protein cross-linking in enamel development.
abstract: Tuft protein is a material associated with enamel tufts, and resides in dental enamel primarily at the enamel-dentine junction. It is located primarily at prism peripheries and extends in a very attenuated form towards the enamel outer surface. While it appears to be a mixture of components, partial sequencing and antibody studies have demonstrated the presence of amelin, a protein associated with prism boundaries. Biochemical investigations have been seriously hampered by the fact that tuft protein is extremely insoluble in a range of solvents, including mineral acids, EDTA, chaotropic agents, and detergents including SDS. This raised the question as to whether it could be chemically cross-linked. Antibodies to γ-glutamyl cross-linking peptide were used to determine the presence of a cross-linking isopeptide. In all cases examined, a positive response indicated that tuft protein does display chemical cross-linking, which may explain the insoluble nature of this material. This may be a mechanism to prevent protein degradation at the enamel-dentine junction during the degradation of enamel matrix, which occurs during amelogenesis.
authors.affiliation: Division of Oral Biology, Leeds Dental Institute, University of Leeds, Leeds, UK. C.Robinson@Leeds.ac.uk
authors.forename: Colin
authors.initials: C
authors.lastname: Robinson
authors.forename: Jackie
authors.initials: J
authors.lastname: Hudson
mesh_terms: D000566:Amelogenesis; D003743:Dental Enamel / Q000737:chemistry*; D003746:Dental Enamel Proteins / Q000032:analysis / Q000737:chemistry*; D003747:Dental Enamel Solubility; D004151:Dipeptides / Q000737:chemistry; D006801:Humans; D015394:Molecular Structure
chemical_list: D003746:Dental Enamel Proteins; D004151:Dipeptides; C001299:epsilon-(gamma-glutamyl)-lysine