Exposure to a Cutinase-like Serine Esterase Triggers Rapid Lysis of Multiple Mycobacterial Species

Abstract

Background: Mycobacteria possess a unique envelope with poorly understood architectural organization of constituent molecules. Results: Exposure to an esterase that targets trehalose mycolates triggers rapid lysis of mycobacteria. Conclusion: Trehalose mycolates are on the exposed surface of mycobacterial envelope with an indispensable structural role. Significance: The study identifies a novel enzyme-based lysis of mycobacteria, with a potential for new anti-tuberculosis applications.

A Hydrolase of Trehalose Dimycolate Induces Nutrient Influx and Stress Sensitivity to Balance Intracellular Growth of Mycobacterium tuberculosis

“…It is therefore reasonable to argue that TDM hydrolases could modulate the solute influx through changes in MoM structure, implying that TDM is likely localized in MoM. This notion is further supported by the accessibility of TDM to exogenous Tdmh Ms (Yang et al, 2012b). An increase in MoM permeability through hydrolase activity can be imagined to occur either through delocalized increase in fluidity of the lipid bilayer, or localized perturbation of the lipid domains around porins to induce channel openings.…”

“…Therefore to affirm the correlation between TDM hydrolase activity and the phenotypes of Δtdmh Mtb , we investigated the effect of ectopic expression of a well-characterized heterologous Tdmh, Tdmh M s , in a nutrient-rich culture of Mtb. Interestingly, despite a deleterious consequence of an exogenous exposure to Tdmh Ms (Yang et al, 2012b), its stable expression from a plasmid borne acetamide-inducible promoter could be achieved in Mtb without any apparent impact on the growth (Fig. 4A and 4B).…”

“…TDM has long been studied as a cord factor – conferring a cord-like appearance to Mtb in vitro – with strong immunomodulatory activities (Hunter et al, 2006; Ishikawa et al, 2009; Rao et al, 2006). However, recent studies suggest that TDM could be a structural component of MoM (Ojha et al, 2010; Yang et al, 2012b). An uncontrolled exogenous exposure of mycobacteria to a serine hydrolase of TDM from M. smegmatis, called Tdmh Ms , leads to a rapid depletion of trehalose mycolates and subsequent rupturing of the envelope (Ojha et al, 2010; Yang et al, 2012b).…”

“…However, recent studies suggest that TDM could be a structural component of MoM (Ojha et al, 2010; Yang et al, 2012b). An uncontrolled exogenous exposure of mycobacteria to a serine hydrolase of TDM from M. smegmatis, called Tdmh Ms , leads to a rapid depletion of trehalose mycolates and subsequent rupturing of the envelope (Ojha et al, 2010; Yang et al, 2012b). Interestingly, one of the products of TDM hydrolysis – free mycolic acid (FM) – is an abundant extracellular component of in vitro biofilms of both Mtb and M. smegmatis , although the physiological role of Tdmh Ms during mycobacterial growth in biofilms is unclear (Ojha et al, 2008; Ojha et al, 2010).…”

Trehalose recycling promotes energy-efficient mycomembrane reorganization in nutrient-limited mycobacteria

“…Decreased TDM abundance has been reported for mycobacteria growing in biofilms or adapting to hypoxia or nutrient limitation (Galagan et al, 2013; Lee et al, 2019; Ojha et al, 2010; Yang et al, 2014). As uncontrolled TDM hydrolysis results in cell lysis (Ojha et al, 2010; Yang et al, 2013), we sought to understand the kinetics of TDM turnover under stress. TMM donates mycolic acids to other molecules of TMM, to form the TDM glycolipid, or to arabinogalactan, to form covalent arabinogalactan mycolates (AGM).…”