화학공학소재연구정보센터
Biochemical and Biophysical Research Communications, Vol.331, No.1, 127-131, 2005
High production of methyl mercaptan by L-methionine-alpha-deamino-gamma-mercaptomethane lyase from Treponema denticola
Methyl mercaptan is derived from L-methionine by the action of L-methionine-α-deamino-γ-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 (0.55 mM) 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. © 2005 Elsevier Inc. All rights reserved.