title: Methyl mercaptan production by periodontal bacteria.
abstract: Oral malodour is principally caused by volatile sulphur compounds (VSC) such as hydrogen sulphide, methyl mercaptan and dimethyl sulphide. Methyl mercaptan is highly toxic, and its presence within a periodontal pocket suggests involvement in the induction and/or progression of periodontal disease. Methyl mercaptan is produced from L-methionine by L-methionine- alpha -deamino- gamma -mercaptomethane-lyase (METase). METase catalyses the alpha,gamma-eliminating reaction of L-methionine, which results in the release of alpha-ketobutyrate, methyl mercaptan and ammonia. Although methyl mercaptan is produced by a variety of microorganisms, Porphyromonas gingivalis is considered to be the most potent producer. METases of P. gingivalis have been characterised and the genes responsible for their production, the mg/genes, have been sequenced. To ascertain the role of METase in P. gingivalis pathogenicity, a METase-deficient mutant strain (M1217) from P. gingivalis strain W83 was engineered. Only 7.7% of the mice infected with W83 survived 4 days after subcutaneous injection, whereas 36% of the mice infected with M1217 survived over the same time period. Many papers have reported the periodontal pathogenesis of VSC. It has been argued that methyl mercaptan may play a significant role in the pathogenicity of P. gingivalis.
authors.affiliation: Department of Preventive Dentistry, Kyushu University Faculty of Dental Science, Fukuoka, Japan. yosh@dent.kyushu-u.ac.jp
authors.forename: Y
authors.initials: Y
authors.lastname: Nakano
authors.forename: M
authors.initials: M
authors.lastname: Yoshimura
authors.forename: T
authors.initials: T
authors.lastname: Koga
mesh_terms: D000641:Ammonia / Q000378:metabolism; D000818:Animals; D016866:Bacteroidaceae Infections / Q000378:metabolism*; D002087:Butyrates / Q000378:metabolism; D013437:Carbon-Sulfur Lyases / Q000172:deficiency / Q000235:genetics / Q000378:metabolism; D006209:Halitosis / Q000378:metabolism* / Q000382:microbiology; D006862:Hydrogen Sulfide / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D009154:Mutation / Q000235:genetics; D010514:Periodontal Pocket / Q000382:microbiology*; D016966:Porphyromonas gingivalis / Q000201:enzymology / Q000378:metabolism* / Q000472:pathogenicity; D013438:Sulfhydryl Compounds / Q000378:metabolism*; D013440:Sulfides / Q000378:metabolism; D014774:Virulence
chemical_list: D002087:Butyrates; D013438:Sulfhydryl Compounds; D013440:Sulfides; C005231:methylmercaptan; D000641:Ammonia; D013437:Carbon-Sulfur Lyases; C021558:L-methionine gamma-lyase; C004784:dimethyl sulfide; D006862:Hydrogen Sulfide