Target-based screen against a periplasmic serine protease that regulates intrabacterial pH homeostasis in Mycobacterium tuberculosis. Academic Article uri icon

Overview

abstract

  • Mycobacterium tuberculosis (Mtb) maintains its intrabacterial pH (pHIB) near neutrality in the acidic environment of phagosomes within activated macrophages. A previously reported genetic screen revealed that Mtb loses this ability when the mycobacterial acid resistance protease (marP) gene is disrupted. In the present study, a high throughput screen (HTS) of compounds against the protease domain of MarP identified benzoxazinones as inhibitors of MarP. A potent benzoxazinone, BO43 (6-chloro-2-(2'-methylphenyl)-4H-1,3-benzoxazin-4-one), acylated MarP and lowered Mtb's pHIB and survival during incubation at pH 4.5. BO43 had similar effects on MarP-deficient Mtb, suggesting the existence of additional target(s). Reaction of an alkynyl-benzoxazinone, BO43T, with Mycobacterium bovis variant bacille Calmette-GuĂ©rin (BCG) followed by click chemistry with azido-biotin identified both the MarP homologue and the high temperature requirement A1 (HtrA1) homologue, an essential protein. Thus, the chemical probe identified through a target-based screen not only reacted with its intended target in the intact cells but also implicated an additional enzyme that had eluded a genetic screen biased against essential genes.

publication date

  • December 5, 2014

Research

keywords

  • Homeostasis
  • Mycobacterium tuberculosis
  • Periplasm
  • Serine Proteases

Identity

PubMed Central ID

  • PMC4340348

Scopus Document Identifier

  • 84923377050

Digital Object Identifier (DOI)

  • 10.1021/cb500746z

PubMed ID

  • 25457457

Additional Document Info

volume

  • 10

issue

  • 2