New lipophilic phthalimido- and 3-phenoxybenzyl sulfonates: inhibition of antigen 85C mycolyltransferase activity and cytotoxicity.

Four new sulfonates were prepared as potential inhibitors of antigen 85C, a mycolyl transferase involved in the biosynthesis of the mycobacterial cell wall being designed on the basis of the proposed catalytic mechanism and antigen 85C crystal structure. The inhibitors contained a sulfonate moiety, 3-phenoxybenzyl alcohol or N-(hydroxyethyl)phthalimide as trehalose mimetics, and an alkyl chain of different length mimicking either the mycolate (alpha-chain or the mycolic acid (beta-branch. One compound displayed promising activity in a mycolyltransferase inhibition assay (compound 2b, IC50 = 4.

Design, synthesis, biochemical evaluation and antimycobacterial action of phosphonate inhibitors of antigen 85C, a crucial enzyme involved in biosynthesis of the mycobacterial cell wall.

Phosphonate inhibitors of antigen 85C were prepared. The inhibitors, comprising a phosphonate moiety, mycolic acid mimetic and a trehalose surrogate, contain substituted benzyl alcohols, N-(omega-hydroxyalky)phthalimide, 2-phenylethanol or 4-(phthalimido)butanol as trehalose mimetics, and an alkyl chain of different lengths mimicking the mycolic acid side chain. The best compounds inhibited the mycolyltransferase activity of antigen 85C with IC(50) in the low micromolar range and inhibited the growth of Mycobacterium avium in culture.

Phosphonate inhibitors of antigen 85C, a crucial enzyme involved in the biosynthesis of the Mycobacterium tuberculosis cell wall.

The first phosphonate inhibitors of antigen 85C--a major protein component of the Mycobacterium tuberculosis cell wall possessing mycolyltransferase activity were prepared using structure-based design. These potential novel antituberculosis agents, consisting of a phosphonate moiety, hydrophobic alkyl chain and a simple trehalose-mimicking aromatic structure, were designed as tetrahedral transition-state analogue inhibitors of antigen 85C, which catalyzes the key mycolyltransferase reaction involved in cell wall biosynthesis.

The structure of Mycobacterium tuberculosis MPT51 (FbpC1) defines a new family of non-catalytic alpha/beta hydrolases.

Mycobacterium tuberculosis, the causative agent of tuberculosis, is known to secrete a number of highly immunogenic proteins that are thought to confer pathogenicity, in part, by mediating binding to host tissues. Among these secreted proteins are the trimeric antigen 85 (Ag85) complex and the related MPT51 protein, also known as FbpC1. While the physiological function of Ag85, a mycolyltransferase required for the biosynthesis of the cell wall component alpha,alpha'-trehalose dimycolate (or cord factor), has been identified recently, the function of the closely related MPT51 (approximately 40% identity with the Ag85 components) remains to be established.

Crystallization and preliminary X-ray diffraction data of Mycobacterium tuberculosis FbpC1 (Rv3803c).

The heterotrimeric antigen 85 complex (Ag85) is a major component of the cell wall of Mycobacterium tuberculosis and consists of three abundantly secreted proteins (FbpA, FbpB and FbpC2). These play key roles in the pathogenesis of tuberculosis and in maintaining cell-wall integrity. A homologue of the Ag85 subunits ( approximately 40% identity) was recently annotated in the M.