Using a Label Free Quantitative Proteomics Approach to Identify Changes in Protein Abundance in Multidrug-Resistant Mycobacterium tuberculosis

Abstract

Reports in recent years indicate that the increasing emergence of resistance to drugs be using to TB treatment. The resistance to them severely affects to options for effective treatment. The emergence of multidrug-resistant tuberculosis has increased interest in understanding the mechanism of drug resistance in M. tuberculosis and the development of new therapeutics, diagnostics and vaccines. In this study, a label-free quantitative proteomics approach has been used to analyze proteome of multidrug-resistant and susceptible clinical isolates of M. tuberculosis and identify differences in protein abundance between the two groups. With this approach, we were able to identify a total of 1,583 proteins. The majority of identified proteins have predicted roles in lipid metabolism, intermediary metabolism, cell wall and cell processes. Comparative analysis revealed that 68 proteins identified by at least two peptides showed significant differences of at least twofolds in relative abundance between two groups. In all protein differences, the increase of some considering proteins such as NADH dehydrogenase, probable aldehyde dehydrogenase, cyclopropane mycolic acid synthase 3, probable arabinosyltransferase A, putative lipoprotein, uncharacterized oxidoreductase and six membrane proteins in resistant isolates might be involved in the drug resistance and to be potential diagnostic protein targets. The decrease in abundance of proteins related to secretion system and immunogenicity (ESAT-6-like proteins, ESX-1 secretion system associated proteins, O-antigen export system and MPT63) in the multidrug-resistant strains can be a defensive mechanism undertaken by the resistant cell.

Metabolic Changes of Mycobacterium tuberculosis during the Anti-Tuberculosis Therapy

“…This protein is an oxidoreductase that is necessary for the growth of mycobacteria and has a potential role in detoxification of toxic metabolites. Previous studies have shown that this enzyme was differentially represented between INHr and INHs strains [23,24] and for STR [25]. In the present study, higher transcript levels of Rv2971 in the 2093, compared to other strains, were detected.…”

The ATP-Binding Cassette (ABC) Transport Systems in Mycobacterium tuberculosis: Structure, Function, and Possible Targets for Therapeutics

“…The inactivation of their respective orthologues in M. smegmatis has suggested that they are involved in the biosynthesis of cell wall components and arabinogalactan, working as a potential flippase candidate that exports the lipid intermediate containing the galactan structure prior to its arabinosylation [97]. RfbE was identified as one of the most expressed proteins in the proteomic analysis of a one-year-old dormant M. tuberculosis [98] bacillus and is highly abundant in multidrug-resistant and susceptible M. tuberculosis isolates [99]. RfbDE seems to be essential for in vitro growth [40,46] and is required for growth in C57BL/6J mouse spleen [34].…”

Label-Free Comparative Proteomics of Differentially Expressed Mycobacterium tuberculosis Protein in Rifampicin-Related Drug-Resistant Strains

“…The supernatant containing the whole cell lysate proteins was retained and determined the concentrations with BCA according to the manufacturer’s instructions. The lysate was sterilized through a filter membrane with the pore diameter of 0.22 μm (Pall Corporation, Ann Arbour, MI, USA) and stored at −80 °C until further analysis [ 76 ]. The lysate proteins were identified by 12% SDS-PAGE.…”