title: High production of methyl mercaptan by L-methionine-alpha-deamino-gamma-mercaptomethane lyase from Treponema denticola.
abstract: Methyl mercaptan is derived from l-methionine by the action of l-methionine-alpha-deamino-gamma-mercaptomethane lyase (METase) and is a major component of oral malodor. This compound is highly toxic and is thought to play an important role in periodontal disease. We found that Treponema denticola, a member of the subgingival biofilm at periodontal disease sites, produced a large amount of methyl mercaptan even at low concentration of l-methionine. METase activity in a cell-free extract from T. denticola was detected by two-dimensional electrophoresis under non-denaturing conditions, and the protein spot that exhibited high METase activity was identified using a matrix-assisted laser desorption/ionization time-of-flight mass spectrometer. The identified gene produced a METase with a K(m) value for l-methionine (0.55mM) that is much lower than those of METases previously identified in the other organisms. This result suggests that T. denticola is an important producer of methyl mercaptan in the subgingival biofilm.
authors.affiliation: Department of Preventive Dentistry, Kyushu University Faculty of Dental Science, Fukuoka 812-8582, Japan.
authors.forename: Haruka
authors.initials: H
authors.lastname: Fukamachi
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Nakano
authors.forename: Soichiro
authors.initials: S
authors.lastname: Okano
authors.forename: Yasuko
authors.initials: Y
authors.lastname: Shibata
authors.forename: Yoshimitsu
authors.initials: Y
authors.lastname: Abiko
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Yamashita
mesh_terms: D001426:Bacterial Proteins / Q000032:analysis / Q000302:isolation & purification / Q000378:metabolism; D013437:Carbon-Sulfur Lyases / Q000032:analysis / Q000302:isolation & purification / Q000378:metabolism*; D016966:Porphyromonas gingivalis / Q000201:enzymology; D020539:Sequence Analysis, Protein; D013438:Sulfhydryl Compounds / Q000378:metabolism*; D048373:Treponema denticola / Q000201:enzymology*
chemical_list: D001426:Bacterial Proteins; D013438:Sulfhydryl Compounds; C005231:methylmercaptan; D013437:Carbon-Sulfur Lyases; C021558:L-methionine gamma-lyase