Article

S-nitroso proteome of Mycobacterium tuberculosis: Enzymes of intermediary metabolism and antioxidant defense

Department of Medicine, Cornell University, Итак, New York, United States
Proceedings of the National Academy of Sciences (Impact Factor: 9.67). 02/2005; 102(2):467-72. DOI: 10.1073/pnas.0406133102
Source: PubMed

ABSTRACT

The immune response to Mycobacterium tuberculosis (Mtb) includes expression of nitric oxide (NO) synthase (NOS)2, whose products can kill Mtb in vitro with a molar potency greater than that of many conventional antitubercular agents. However, the targets of reactive nitrogen intermediates (RNIs) in Mtb are unknown. One major action of RNIs is protein S-nitrosylation. Here, we describe, to our knowledge, the first proteomic analysis of S-nitrosylation in a whole organism after treating Mtb with bactericidal concentrations of RNIs. The 29 S-nitroso proteins identified are all enzymes, mostly serving intermediary metabolism, lipid metabolism, and/or antioxidant defense. Many are essential or implicated in virulence, including defense against RNIs. For each of two target enzymes tested, lipoamide dehydrogenase and mycobacterial proteasome ATPase, S-nitrosylation caused enzyme inhibition. Moreover, endogenously biotinylated proteins were driven into mixed disulfide complexes. Targeting of metabolic enzymes and antioxidant defenses by means of protein S-nitrosylation and mixed disulfide bonding may contribute to the antimycobacterial actions of RNIs.

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Available from: Hediye Erdjument-Bromage, May 22, 2014
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    • "In E. coli, nitrate reductase is an important source of species reactive enough to nitrosylate proteins, as evidenced by an 80% reduction in protein S-nitrosylation in narG-deficient as compared to wild-type bacteria (Ralt et al. 1988; Corker 2003; Seth et al. 2012). Rhee et al. (2005) identified 29 mycobacterial proteins that were S-nitrosylated when Mtb was treated with nitrite at low pH, including KatG. In addition, heme peroxidases such as KatG oxidize nitrite to more reactive species, such as nitrogen dioxide (•NO2) and nitryl chloride (NO2Cl) (Klebanoff 1993; van der Vliet et al. 1997; Eiserich et al. 1998; Battistuzzi et al. 2010). "
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    • "This strategy was used to verify the role of H2O2 or NO2 stimulus on fungal growth and cell signaling. Yeast cells were exposed to different concentrations of H2O2 or NaNO2 (in culture medium mildly acidic, pH 5.5; in this condition NaNO2 releases NO), for 5 h at 37°C [22], [23], [24]. Then yeast cells were washed and incubated for 24 h at 37°C under shaking in fresh culture media. "
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    • "of biological activities. In its reduced form, sulfur is used in the biosynthesis of the amino acid cysteine, one of the prime targets for reactive nitrogen intermediates encountered by M. tuberculosis in the intracellular environment [11] . Cysteine is subsequently incorporated into mycothiol, which functions analogously to glutathione [12] and is crucial to M. tuberculosis within the granuloma for regulating the redox balance on encountering free radicals released by host cells. "
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