The trehalose-specific transporter LpqY-SugABC is required for antimicrobial and anti-biofilm activity of trehalose analogues in Mycobacterium smegmatis

Abstract

Mycobacteria, including the bacterial pathogen that causes human tuberculosis, possess distinctive pathways for synthesizing and utilizing the non-mammalian disaccharide trehalose. Trehalose metabolism is essential for mycobacterial viability and has been linked to in vitro biofilm formation, which may bear relevance to in vivo drug tolerance. Previous research has shown that some trehalose analogues bearing modifications at the 6-position inhibit growth of various mycobacterial species. In this work, 2-, 5-, and 6-position-modified trehalose analogues were synthesized using our previously reported one-step chemoenzymatic method and shown to inhibit growth and biofilm formation in the two- to three-digit micromolar range in Mycobacterium smegmatis. The trehalose-specific ABC transporter LpqY-SugABC was essential for antimicrobial and anti-biofilm activity, suggesting that inhibition by monosubstituted trehalose analogues requires cellular uptake and does not proceed via direct action on extracellular targets such as antigen 85 acyltransferases or trehalose dimycolate hydrolase. Although the potency of the described compounds in in vitro growth and biofilm assays is moderate, this study reports the first trehalose-based mycobacterial biofilm inhibitors and reinforces the concept of exploiting unique sugar uptake pathways to deliver inhibitors and other chemical cargo to mycobacteria.

Hit Generation in TB Drug Discovery: From Genome to Granuloma

“…LpqY-SugABC transports trehalose back into the mycobacterial cell after hydrolysis of trehalose monomycolate (TMM) which is exported by the MmpL3 transporter. The LpqY-SugABC transporter accepts structural analogs of trehalose 250 suggesting that it may be used for drug delivery purposes. Existing synthetic methods and applications, 251 as well as validation the pathway is required to maintain viability, 252 suggest that trehalose conjugates could be a fruitful direction to pursue.…”

Transient drug-tolerance and permanent drug-resistance rely on the trehalose-catalytic shift in Mycobacterium tuberculosis

“…A series of trehalose analogs, including 6-treAz (6-azido-6-α,α’-trehalose), were recently synthesized chemoenzymatically and shown to have selective inhibitory activity against M. smegmatis biofilm formation with no discernible interference in planktonic growth (Supplementary Fig. 10a) 43,44 . Based upon the structural similarity between 6-treAz and trehalose, we hypothesized that the anti-mycobacterial biofilm activity of 6-treAz is attributable to its competitive inhibition of the TreS-mediated trehalose-catalytic shift.…”

Synthesis and in Vitro Characterization of Trehalose‐Based Inhibitors of Mycobacterial Trehalose 6‐Phosphate Phosphatases

“…A second 6,6‐bisalkyl library of α,α′‐trehalose derivatives was found to be active against Mycobacterium smegmatis . In addition, 6,6‐bis(α‐ketoester/amide) analogues of α,α′‐trehalose have been reported to be active against Ag85C, whereas 6‐deoxy‐, 6‐deoxy‐6‐fluoro‐, and 6‐azido‐6‐deoxy‐α,α′‐trehalose were shown to inhibit (MIC 50–100 μ m ) M. smegmatis biofilm formation . Collectively, these studies suggest several possible applications of the target compounds.…”