Methyl mercaptan production by periodontal bacteria
Methyl mercaptan production by periodontal bacteria
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DOI：
10.1002/j.1875-595x.2002.tb00928.x
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发表时间：
2002-06-01
影响因子：
3.3
通讯作者：
Koga, T
中科院分区：
文献类型：
--
作者：
Nakano, Y;Yoshimura, M;Koga, T
口腔异味主要是由硫化氢、甲硫醇和二甲硫醚等挥发性硫化合物(VSC)引起的。甲硫醇具有剧毒，其存在于牙周袋内表明参与牙周病的诱发和/或进展。甲硫醇由 L-甲硫氨酸通过 L-甲硫氨酸-α-脱氨基-γ-聚硫甲烷裂解酶 (METase) 生产。 METase 催化 L-蛋氨酸的 α,γ 消除反应，从而释放 α-酮丁酸、甲硫醇和氨。尽管甲硫醇是由多种微生物产生的，但牙龈卟啉单胞菌被认为是最有效的产生者。牙龈卟啉单胞菌的 METase 已被表征，并且负责其产生的基因 mgl 基因已被测序。为了确定 METase 在牙龈卟啉单胞菌致病性中的作用，从牙龈卟啉单胞菌菌株 W83 中构建了 METase 缺陷突变株 (M1217)。皮下注射 4 天后，感染 W83 的小鼠仅有 7.7% 存活，而感染 M1217 的小鼠在同一时间段内有 36% 存活。许多论文报道了VSC的牙周发病机制。有人认为甲硫醇可能在牙龈卟啉单胞菌的致病性中发挥重要作用。
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-mereaptomethane-lyase (METase). METase catalyses the alpha,gamma-eliminating reaction of L-methionine, which results in the release of a-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 mgl 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.