Researchers from Imperial, the London School of Hygiene & Tropical Medicine (LSHTM), and pharmaceutical collaborators have identified a novel drug target, the PurF enzyme, to combat tuberculosis. Published in Nature, the discovery points toward chemical compounds like JNJ-6640 that effectively inhibit bacterial replication, offering a promising strategy against drug-resistant strains.
The Global Burden of Tuberculosis and the Resistance Crisis
Tuberculosis remains one of the top ten causes of death worldwide and ranks among the three deadliest infectious diseases, causing over 1.25 million deaths in 2023. The causative bacterium, Mycobacterium tuberculosis, presents severe treatment challenges. Dr Gerald Larrouy-Maumus in Imperial’s Department of Life Sciences noted, “TB is still a major global problem. Millions are affected every year, disproportionately in low- and middle-income countries, and it’s an under-recognised problem even in the UK.” Completely clearing an infection requires a prolonged course involving multiple antibiotics. Side effects frequently cause patients to discontinue treatment prematurely, creating selective pressure for drug-resistant strains to evolve and spread.
Inhibiting the PurF Enzyme to Block Bacterial Replication
To bypass existing drug resistance mechanisms, researchers screened thousands of chemical compounds to identify those capable of killing M. tuberculosis. This collaborative effort involving Imperial, LSHTM, and Janssen Pharmaceutica (now Johnson & Johnson Innovative Medicine) revealed that a molecule designated as JNJ-6640 successfully halts bacterial replication. “There were a lot of hits but one we were quite excited about. We found one that’s incredibly potent against TB,” explained Dr William Pearson at LSHTM. Using advanced techniques including genetic analysis, protein studies, and microscopy, the team demonstrated that these compounds work by inhibiting the PurF enzyme. Bacteria utilize this specific enzyme to synthesize purines, which are essential molecules required by all cells for core metabolic and signaling functions.
In Plain English: The Clinical Takeaway
- The Target: Scientists found that blocking a specific bacterial enzyme called PurF starves Mycobacterium tuberculosis of the basic building blocks it needs to multiply.
- Overcoming Resistance: Because current standard treatments face growing antibiotic resistance, attacking a completely new biological pathway can bypass existing defensive mutations in the bacteria.
- Next Steps: While the test molecule JNJ-6640 is currently unstable when ingested, its discovery establishes a verified chemical blueprint for developers to engineer viable, stable drug candidates.
Metabolomics and Preclinical Validation
While certain bacteria manage to survive by scavenging purines from a human or animal host, the research team verified that M. tuberculosis cannot recover enough purines this way. Utilizing human and mouse lung tissue samples, researchers confirmed the bacterium’s vulnerability. Subsequent in vivo trials using animal models proved that JNJ-6640 successfully reduces tuberculosis infection in mice. Advanced analytical equipment played a crucial role in validating these cellular mechanisms. “The metabolomics using the Agilent instrumentation allowed us to see in chemical terms the products of the PurF enzyme decrease in response to the test compound. This helped us to identify what part of the bacteria were targeted,” stated co-author Dr Richard Wall at LSHTM.
| Research Parameter | Observed Outcome |
|---|---|
| Primary Target | PurF enzyme in Mycobacterium tuberculosis |
| Active Molecule Identified | JNJ-6640 |
| Mechanism of Action | Inhibition of purine biosynthesis, halting replication |
| Preclinical Model Efficacy | Effective at reducing infection loads in murine models |
| Funding Partners | Janssen, Bill & Melinda Gates Foundation, Wellcome |
Contraindications & When to Consult a Doctor
The discovery of the PurF drug target represents early-stage laboratory and preclinical research rather than an immediately available clinical treatment.
Financial Support and Collaborative Development
The published research was made possible through major funding from Janssen Pharmaceutica, the Bill and Melinda Gates Foundation, and Wellcome. Additional technical support was provided by the Agilent Measurement Suite at Imperial’s White City Campus, supplying advanced analytical infrastructure. With the research now published in Nature and accessible to drug development experts globally, ongoing efforts focus on optimizing chemical compounds against this novel drug target to advance future clinical pipelines.
References
- Imperial College London.
- PubMed Central.
This coverage does not constitute formal medical advice, diagnosis, or treatment recommendations. Always consult a licensed physician regarding any health concerns or therapeutic regimens.
