| Structural highlights
Function
[DLDH_MYCTU] Lipoamide dehydrogenase is an essential component of the alpha-ketoacid dehydrogenase complexes, namely the pyruvate dehydrogenase (PDH) complex, the branched-chain alpha-ketoacid dehydrogenase (BCKADH) complex, and likely also the 2-oxoglutarate dehydrogenase (ODH) complex. Catalyzes the reoxidation of dihydrolipoyl groups which are covalently attached to the lipoate acyltransferase components (E2) of the complexes. Is also able to catalyze the transhydrogenation of NADH and thio-NAD(+) in the absence of D,L-lipoamide, and the NADH-dependent reduction of quinones in vitro.[1] [2] [3] [4] [5] Together with AhpC, AhpD and DlaT, Lpd constitutes an NADH-dependent peroxidase active against hydrogen and alkyl peroxides as well as serving as a peroxynitrite reductase, thus protecting the bacterium against reactive nitrogen intermediates and oxidative stress generated by the host immune system.[6] [7] [8] [9] [10] Appears to be essential for Mtb pathogenesis.[11] [12] [13] [14] [15]
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
Mycobacterium tuberculosis (Mtb) remains the leading single cause of death from bacterial infection. Here we explored the possibility of species-selective inhibition of lipoamide dehydrogenase (Lpd), an enzyme central to Mtb's intermediary metabolism and antioxidant defense. High-throughput screening of combinatorial chemical libraries identified triazaspirodimethoxybenzoyls as high-nanomolar inhibitors of Mtb's Lpd that were noncompetitive versus NADH, NAD(+), and lipoamide and >100-fold selective compared to human Lpd. Efficacy required the dimethoxy and dichlorophenyl groups. The structure of an Lpd-inhibitor complex was resolved to 2.42 A by X-ray crystallography, revealing that the inhibitor occupied a pocket adjacent to the Lpd NADH/NAD(+) binding site. The inhibitor did not overlap with the adenosine moiety of NADH/NAD(+) but did overlap with positions predicted to bind the nicotinamide rings in NADH and NAD(+) complexes. The dimethoxy ring occupied a deep pocket adjacent to the FAD flavin ring where it would block coordination of the NADH nicotinamide ring, while the dichlorophenyl group occupied a more exposed pocket predicted to coordinate the NAD(+) nicotinamide. Several residues that are not conserved between the bacterial enzyme and its human homologue were predicted to contribute both to inhibitor binding and to species selectivity, as confirmed for three residues by analysis of the corresponding mutant Mtb Lpd proteins. Thus, nonconservation of residues lining the electron-transfer tunnel in Mtb Lpd can be exploited for development of species-selective Lpd inhibitors.
Triazaspirodimethoxybenzoyls as selective inhibitors of mycobacterial lipoamide dehydrogenase .,Bryk R, Arango N, Venugopal A, Warren JD, Park YH, Patel MS, Lima CD, Nathan C Biochemistry. 2010 Mar 2;49(8):1616-27. PMID:20078138[16]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Argyrou A, Blanchard JS. Mycobacterium tuberculosis lipoamide dehydrogenase is encoded by Rv0462 and not by the lpdA or lpdB genes. Biochemistry. 2001 Sep 25;40(38):11353-63. PMID:11560483
- ↑ Bryk R, Lima CD, Erdjument-Bromage H, Tempst P, Nathan C. Metabolic enzymes of mycobacteria linked to antioxidant defense by a thioredoxin-like protein. Science. 2002 Feb 8;295(5557):1073-7. Epub 2002 Jan 17. PMID:11799204 doi:10.1126/science.1067798
- ↑ Tian J, Bryk R, Shi S, Erdjument-Bromage H, Tempst P, Nathan C. Mycobacterium tuberculosis appears to lack alpha-ketoglutarate dehydrogenase and encodes pyruvate dehydrogenase in widely separated genes. Mol Microbiol. 2005 Aug;57(3):859-68. PMID:16045627 doi:http://dx.doi.org/MMI4741
- ↑ Venugopal A, Bryk R, Shi S, Rhee K, Rath P, Schnappinger D, Ehrt S, Nathan C. Virulence of Mycobacterium tuberculosis depends on lipoamide dehydrogenase, a member of three multienzyme complexes. Cell Host Microbe. 2011 Jan 20;9(1):21-31. doi: 10.1016/j.chom.2010.12.004. PMID:21238944 doi:http://dx.doi.org/10.1016/j.chom.2010.12.004
- ↑ Rajashankar KR, Bryk R, Kniewel R, Buglino JA, Nathan CF, Lima CD. Crystal structure and functional analysis of lipoamide dehydrogenase from Mycobacterium tuberculosis. J Biol Chem. 2005 Oct 7;280(40):33977-83. Epub 2005 Aug 10. PMID:16093239 doi:10.1074/jbc.M507466200
- ↑ Argyrou A, Blanchard JS. Mycobacterium tuberculosis lipoamide dehydrogenase is encoded by Rv0462 and not by the lpdA or lpdB genes. Biochemistry. 2001 Sep 25;40(38):11353-63. PMID:11560483
- ↑ Bryk R, Lima CD, Erdjument-Bromage H, Tempst P, Nathan C. Metabolic enzymes of mycobacteria linked to antioxidant defense by a thioredoxin-like protein. Science. 2002 Feb 8;295(5557):1073-7. Epub 2002 Jan 17. PMID:11799204 doi:10.1126/science.1067798
- ↑ Tian J, Bryk R, Shi S, Erdjument-Bromage H, Tempst P, Nathan C. Mycobacterium tuberculosis appears to lack alpha-ketoglutarate dehydrogenase and encodes pyruvate dehydrogenase in widely separated genes. Mol Microbiol. 2005 Aug;57(3):859-68. PMID:16045627 doi:http://dx.doi.org/MMI4741
- ↑ Venugopal A, Bryk R, Shi S, Rhee K, Rath P, Schnappinger D, Ehrt S, Nathan C. Virulence of Mycobacterium tuberculosis depends on lipoamide dehydrogenase, a member of three multienzyme complexes. Cell Host Microbe. 2011 Jan 20;9(1):21-31. doi: 10.1016/j.chom.2010.12.004. PMID:21238944 doi:http://dx.doi.org/10.1016/j.chom.2010.12.004
- ↑ Rajashankar KR, Bryk R, Kniewel R, Buglino JA, Nathan CF, Lima CD. Crystal structure and functional analysis of lipoamide dehydrogenase from Mycobacterium tuberculosis. J Biol Chem. 2005 Oct 7;280(40):33977-83. Epub 2005 Aug 10. PMID:16093239 doi:10.1074/jbc.M507466200
- ↑ Argyrou A, Blanchard JS. Mycobacterium tuberculosis lipoamide dehydrogenase is encoded by Rv0462 and not by the lpdA or lpdB genes. Biochemistry. 2001 Sep 25;40(38):11353-63. PMID:11560483
- ↑ Bryk R, Lima CD, Erdjument-Bromage H, Tempst P, Nathan C. Metabolic enzymes of mycobacteria linked to antioxidant defense by a thioredoxin-like protein. Science. 2002 Feb 8;295(5557):1073-7. Epub 2002 Jan 17. PMID:11799204 doi:10.1126/science.1067798
- ↑ Tian J, Bryk R, Shi S, Erdjument-Bromage H, Tempst P, Nathan C. Mycobacterium tuberculosis appears to lack alpha-ketoglutarate dehydrogenase and encodes pyruvate dehydrogenase in widely separated genes. Mol Microbiol. 2005 Aug;57(3):859-68. PMID:16045627 doi:http://dx.doi.org/MMI4741
- ↑ Venugopal A, Bryk R, Shi S, Rhee K, Rath P, Schnappinger D, Ehrt S, Nathan C. Virulence of Mycobacterium tuberculosis depends on lipoamide dehydrogenase, a member of three multienzyme complexes. Cell Host Microbe. 2011 Jan 20;9(1):21-31. doi: 10.1016/j.chom.2010.12.004. PMID:21238944 doi:http://dx.doi.org/10.1016/j.chom.2010.12.004
- ↑ Rajashankar KR, Bryk R, Kniewel R, Buglino JA, Nathan CF, Lima CD. Crystal structure and functional analysis of lipoamide dehydrogenase from Mycobacterium tuberculosis. J Biol Chem. 2005 Oct 7;280(40):33977-83. Epub 2005 Aug 10. PMID:16093239 doi:10.1074/jbc.M507466200
- ↑ Bryk R, Arango N, Venugopal A, Warren JD, Park YH, Patel MS, Lima CD, Nathan C. Triazaspirodimethoxybenzoyls as selective inhibitors of mycobacterial lipoamide dehydrogenase . Biochemistry. 2010 Mar 2;49(8):1616-27. PMID:20078138 doi:10.1021/bi9016186
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