title: Beta-hexosaminidase activity of the oral pathogen Tannerella forsythia influences biofilm formation on glycoprotein substrates.
abstract: Tannerella forsythia is an important pathogen in periodontal disease. Previously, we showed that its sialidase activity is key to utilization of sialic acid from a range of human glycoproteins for biofilm growth and initial adhesion. Removal of terminal sialic acid residues often exposes β-linked glucosamine or galactosamine, which may also be important adhesive molecules. In turn, these residues are often removed by a group of enzymes known as β-hexosaminidases. We show here that T. forsythia has the ability to cleave glucosamine and galactosamine from model substrates and that this activity can be inhibited by the hexosaminidase inhibitor PugNAc (O-(2-acetamido-2-deoxy-d-glucopyranosylidene)amino N-phenyl carbamate). We now demonstrate for the first time that β-hexosaminidase activity plays a role in biofilm growth on glycoprotein-coated surfaces because biofilm growth and initial cell adhesion are inhibited by PugNAc. In contrast, adhesion to siallo-glycoprotein-coated surfaces is unaltered by PugNAc in the absence of sialidase activity (using a sialidase-deficient mutant) or surprisingly on the clinically relevant substrates saliva or serum. These data indicate that β-hexosaminidase activity has a significant role in biofilm formation in combination with sialidase activity in the biofilm lifestyle of T. forsythia.
authors.affiliation: Oral and Maxillofacial Pathology, School of Clinical Dentistry, University of Sheffield, Sheffield, UK.
authors.forename: Sumita
authors.initials: S
authors.lastname: Roy
authors.forename: Chatchawal
authors.initials: C
authors.lastname: Phansopa
authors.forename: Prachi
authors.initials: P
authors.lastname: Stafford
authors.forename: Kiyonobu
authors.initials: K
authors.lastname: Honma
authors.forename: C W Ian
authors.initials: CW
authors.lastname: Douglas
authors.forename: Ashu
authors.initials: A
authors.lastname: Sharma
authors.forename: Graham P
authors.initials: GP
authors.lastname: Stafford
mesh_terms: D000117:Acetylglucosamine / Q000031:analogs & derivatives / Q000378:metabolism; D041963:Bacteroidetes / Q000187:drug effects / Q000201:enzymology* / Q000502:physiology*; D018441:Biofilms / Q000187:drug effects / Q000254:growth & development*; D005688:Galactosamine / Q000378:metabolism; D005944:Glucosamine / Q000378:metabolism; D006023:Glycoproteins / Q000378:metabolism*; D006801:Humans; D010091:Oximes / Q000378:metabolism; D048448:Phenylcarbamates / Q000378:metabolism; D001619:beta-N-Acetylhexosaminidases / Q000037:antagonists & inhibitors / Q000378:metabolism*
chemical_list: D006023:Glycoproteins; D010091:Oximes; D048448:Phenylcarbamates; C068836:N-acetylglucosaminono-1,5-lactone O-(phenylcarbamoyl)oxime; D005688:Galactosamine; D001619:beta-N-Acetylhexosaminidases; D005944:Glucosamine; D000117:Acetylglucosamine