TY - JOUR
T1 - Role of glutathione metabolism of Treponema denticola in bacterial growth and virulence expression
AU - Chu, Lianrui
AU - Dong, Zheng
AU - Xu, Xiaoping
AU - Cochran, David L.
AU - Ebersole, Jefferey L.
PY - 2002
Y1 - 2002
N2 - Hydrogen sulfide (H2S) is a major metabolic end product detected in deep periodontal pockets that is produced by resident periodontopathic microbiota associated with the progression of periodontitis. Treponema denticola, a member of the subgingival biofilm at disease sites, produces cystalysin, an enzyme that catabolizes cysteine, releasing H2S. The metabolic pathway leading to H2S formation in periodontal pockets has not been determined. We used a variety of thiol compounds as substrates for T. denticola to produce H2S. Our results indicate that glutathione, a readily available thiol source in periodontal pockets, is a suitable substrate for H2S production by this microorganism. In addition to H2S, glutamate, glycine, ammonia, and pyruvate were metabolic end products of metabolism of glutathione. Cysteinyl glycine (Cys-Gly) was also catabolized by the bacteria, yielding glycine, H2S, ammonia, and pyruvate. However, purified cystalysin could not catalyze glutathione and Cys-Gly degradation in vitro. Moreover, the enzymatic activity(ies) in T. denticola responsible for glutathione breakdown was inactivated by trypsin or proteinase K, by heating (56°C) and freezing (-20°C), by sonication, and by exposure to Nα-p-tosyl-L-lysine chloromethyl ketone (TLCK). These treatments had no effect on degradation of cysteine by the purified enzyme. In this study we delineated an enzymatic pathway for glutathione metabolism in the oral spirochete T. denticola; our results suggest that glutathione metabolism plays a role in bacterial nutrition and potential virulence expression.
AB - Hydrogen sulfide (H2S) is a major metabolic end product detected in deep periodontal pockets that is produced by resident periodontopathic microbiota associated with the progression of periodontitis. Treponema denticola, a member of the subgingival biofilm at disease sites, produces cystalysin, an enzyme that catabolizes cysteine, releasing H2S. The metabolic pathway leading to H2S formation in periodontal pockets has not been determined. We used a variety of thiol compounds as substrates for T. denticola to produce H2S. Our results indicate that glutathione, a readily available thiol source in periodontal pockets, is a suitable substrate for H2S production by this microorganism. In addition to H2S, glutamate, glycine, ammonia, and pyruvate were metabolic end products of metabolism of glutathione. Cysteinyl glycine (Cys-Gly) was also catabolized by the bacteria, yielding glycine, H2S, ammonia, and pyruvate. However, purified cystalysin could not catalyze glutathione and Cys-Gly degradation in vitro. Moreover, the enzymatic activity(ies) in T. denticola responsible for glutathione breakdown was inactivated by trypsin or proteinase K, by heating (56°C) and freezing (-20°C), by sonication, and by exposure to Nα-p-tosyl-L-lysine chloromethyl ketone (TLCK). These treatments had no effect on degradation of cysteine by the purified enzyme. In this study we delineated an enzymatic pathway for glutathione metabolism in the oral spirochete T. denticola; our results suggest that glutathione metabolism plays a role in bacterial nutrition and potential virulence expression.
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U2 - 10.1128/IAI.70.3.1113-1120.2002
DO - 10.1128/IAI.70.3.1113-1120.2002
M3 - Article
C2 - 11854190
AN - SCOPUS:0036180411
SN - 0019-9567
VL - 70
SP - 1113
EP - 1120
JO - Infection and Immunity
JF - Infection and Immunity
IS - 3
ER -