| Structural highlights
Function
PSA_MYCTU Component of the proteasome core, a large protease complex with broad specificity involved in protein degradation. The M.tuberculosis proteasome is able to cleave oligopeptides not only after hydrophobic but also after basic, acidic and small neutral residues. Among the identified substrates of the M.tuberculosis proteasome are the pupylated FabD, PanB and Mpa proteins. One function of the proteasome is to contribute to M.tuberculosis ability to resist killing by host macrophages, since the core proteasome is essential for persistence of the pathogen during the chronic phase of infection in mice. The mechanism of protection against bactericidal chemistries of the host's immune response probably involves the degradation of proteins that are irreversibly oxidized, nitrated, or nitrosated.[1] [2]
Publication Abstract from PubMed
Treatment of tuberculosis (TB) currently takes at least 6 months. Latent Mycobacterium tuberculosis (Mtb) is phenotypically tolerant to most anti-TB drugs. A key hypothesis is that drugs that kill nonreplicating (NR) Mtb may shorten treatment when used in combination with conventional drugs. The Mtb proteasome (Mtb20S) could be such a target because its pharmacological inhibition kills NR Mtb and its genetic deletion renders Mtb unable to persist in mice. Here, we report a series of macrocyclic peptides that potently and selectively target the Mtb20S over human proteasomes, including macrocycle 6. The cocrystal structure of macrocycle 6 with Mtb20S revealed structural bases for the species selectivity. Inhibition of 20S within Mtb by 6 dose dependently led to the accumulation of Pup-tagged GFP that is degradable but resistant to depupylation and death of nonreplicating Mtb under nitrosative stress. These results suggest that compounds of this class have the potential to develop as anti-TB therapeutics.
Macrocyclic Peptides that Selectively Inhibit the Mycobacterium tuberculosis Proteasome.,Zhang H, Hsu HC, Kahne SC, Hara R, Zhan W, Jiang X, Burns-Huang K, Ouellette T, Imaeda T, Okamoto R, Kawasaki M, Michino M, Wong TT, Toita A, Yukawa T, Moraca F, Vendome J, Saha P, Sato K, Aso K, Ginn J, Meinke PT, Foley M, Nathan CF, Darwin KH, Li H, Lin G J Med Chem. 2021 May 13;64(9):6262-6272. doi: 10.1021/acs.jmedchem.1c00296. Epub , 2021 May 5. PMID:33949190[3]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Lin G, Hu G, Tsu C, Kunes YZ, Li H, Dick L, Parsons T, Li P, Chen Z, Zwickl P, Weich N, Nathan C. Mycobacterium tuberculosis prcBA genes encode a gated proteasome with broad oligopeptide specificity. Mol Microbiol. 2006 Mar;59(5):1405-16. PMID:16468985 doi:http://dx.doi.org/10.1111/j.1365-2958.2005.05035.x
- ↑ Gandotra S, Schnappinger D, Monteleone M, Hillen W, Ehrt S. In vivo gene silencing identifies the Mycobacterium tuberculosis proteasome as essential for the bacteria to persist in mice. Nat Med. 2007 Dec;13(12):1515-20. Epub 2007 Dec 2. PMID:18059281 doi:http://dx.doi.org/10.1038/nm1683
- ↑ Zhang H, Hsu HC, Kahne SC, Hara R, Zhan W, Jiang X, Burns-Huang K, Ouellette T, Imaeda T, Okamoto R, Kawasaki M, Michino M, Wong TT, Toita A, Yukawa T, Moraca F, Vendome J, Saha P, Sato K, Aso K, Ginn J, Meinke PT, Foley M, Nathan CF, Darwin KH, Li H, Lin G. Macrocyclic Peptides that Selectively Inhibit the Mycobacterium tuberculosis Proteasome. J Med Chem. 2021 May 13;64(9):6262-6272. PMID:33949190 doi:10.1021/acs.jmedchem.1c00296
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