Anti-Tuberculosis Potential of OJT008 against Active and Multi-Drug-Resistant Mycobacterium Tuberculosis: In Silico and In Vitro Inhibition of Methionine Aminopeptidase
Despite the recent progress in the diagnosis of tuberculosis (TB), the chemotherapeutic management of TB continues to be challenging. <i>Mycobacterium tuberculosis</i> (<i>Mtb</i>), the etiological agent of TB, is classified as the 13th leading cause of death globally. In add...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-12-01
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| Series: | International Journal of Molecular Sciences |
| Subjects: | |
| Online Access: | https://www.mdpi.com/1422-0067/24/24/17142 |
| Summary: | Despite the recent progress in the diagnosis of tuberculosis (TB), the chemotherapeutic management of TB continues to be challenging. <i>Mycobacterium tuberculosis</i> (<i>Mtb</i>), the etiological agent of TB, is classified as the 13th leading cause of death globally. In addition, 450,000 people were reported to develop multi-drug-resistant TB globally. The current project focuses on targeting methionine aminopeptidase (MetAP), an essential protein for the viability of <i>Mtb</i>. MetAP is a metalloprotease that catalyzes the excision of the N-terminal methionine (NME) during protein synthesis, allowing the enzyme to be an auspicious target for the development of novel therapeutic agents for the treatment of TB. <i>Mtb</i> possesses two MetAP1 isoforms, MtMetAP1a and MtMetAP1c, which are vital for <i>Mtb</i> viability and, hence, a promising chemotherapeutic target for <i>Mtb</i> therapy. In this study, we cloned and overexpressed recombinant MtMetAP1c. We investigated the in vitro inhibitory effect of the novel MetAP inhibitor, OJT008, on the cobalt ion- and nickel ion-activated MtMetAP1c, and the mechanism of action was elucidated through an in silico approach. The compound’s potency against replicating and multi-drug-resistant (MDR) <i>Mtb</i> strains was also investigated. The induction of the overexpressed recombinant MtMetAP1c was optimized at 8 h with a final concentration of 1 mM Isopropyl β-D-1-thiogalactopyranoside. The average yield from 1 L of <i>Escherichia coli</i> culture for MtMetAP1c was 4.65 mg. A preliminary MtMetAP1c metal dependency screen showed optimum activation with nickel and cobalt ions occurred at 100 µM. The half-maximal inhibitory concentration (IC<sub>50</sub>) values of OJT008 against MtMetAP1c activated with CoCl<sub>2</sub> and NiCl<sub>2</sub> were 11 µM and 40 µM, respectively. The in silico study showed OJT008 strongly binds to both metal-activated MtMetAP1c, as evidenced by strong molecular interactions and a higher binding score, thereby corroborating our result. This in silico study validated the pharmacophore’s metal specificity. The potency of OJT008 against both active and MDR <i>Mtb</i> was <0.063 µg/mL. Our study reports OJT008 as an inhibitor of MtMetAP1c, which is potent at low micromolar concentrations against both active susceptible and MDR <i>Mtb</i>. These results suggest OJT008 is a potential lead compound for the development of novel small molecules for the therapeutic management of TB. |
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| ISSN: | 1661-6596 1422-0067 |