Enhanced cellular uptake of a new, in silico identified antitubercular candidate by peptide conjugation.

Abstract

Mycobacterium tuberculosis is a successful pathogen, and it can survive in infected macrophages in dormant phase for years and decades. The therapy of tuberculosis takes at least six months, and the slow-growing bacterium is resistant to many antibiotics. The development of novel antimicrobials to counter the emergence of bacteria resistant to current therapies is urgently needed. In silico docking methods and structure-based drug design are useful bioinformatics tools for identifying new agents. A docking experiment to M. tuberculosis dUTPase enzyme, which plays a key role in the bacterial metabolism, has resulted in 10 new antitubercular drug candidates. The uptake of antituberculars by infected macrophages is limited by extracellular diffusion. The optimization of the cellular uptake by drug delivery systems can decrease the used dosages and the length of the therapy, and it can also enhance the bioavailability of the drug molecule. In this study, improved in vitro efficacy was achieved by attaching the TB5 antitubercular drug candidate to peptide carriers. As drug delivery components, (i) an antimicrobial granulysin peptide and (ii) a receptor specific tuftsin peptide were used. An efficient synthetic approach was developed to conjugate the in silico identified TB5 coumarone derivative to the carrier peptides. The compounds were effective on M. tuberculosis H37Rv culture in vitro; the chemical linkage did not affect the antimycobacterial activity. Here, we show that the OT20 tuftsin and GranF2 granulysin peptide conjugates have dramatically enhanced uptake into human MonoMac6 cells. The TB5-OT20 tuftsin conjugate exhibited significant antimycobacterial activity on M. tuberculosis H37Rv infected MonoMac6 cells and inhibited intracellular bacteria.

• Authors: Kata Horváti, Bernadett Bacsa, Nóra Szabó, Sándor Dávid, Gábor Mező, Vince Grolmusz, Beáta Vértessy, Ferenc Hudecz, Szilvia Bősze
• Journal: Bioconjugate chemistry (Bioconjug Chem) Vol. 23 Issue 5 Pg. 900-7 (May 16 2012) ISSN: 1520-4812 [Electronic] United States
• PMID: 22515329 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Antitubercular Agents
• Peptides
• Pyrophosphatases
• dUTP pyrophosphatase

Topics

• Amino Acid Sequence
• Antitubercular Agents (chemistry, pharmacokinetics, pharmacology)
• Computer Simulation
• Drug Design
• Humans
• Molecular Docking Simulation
• Molecular Sequence Data
• Mycobacterium tuberculosis (drug effects, enzymology)
• Peptides (chemistry, pharmacokinetics, pharmacology)
• Pyrophosphatases (metabolism)
• Tuberculosis (drug therapy)