22 research outputs found
The application of winning key metrics in a metallurgical firm
This article is focused on creating a system of metrics and its application in a metallurgical firm. Its aim is to highlight the dangers associated with the creation and application of an effective system of metrics. Its objective is also to demonstrate the process (initial steps) in the development of this system in the real family metallurgical firm. In the experimental part an example of causal links among key metrics in the chosen metallurgical firm is presented. Risks associated with the selection of appropriate metrics are presented for discussion
The application of winning key metrics in a metallurgical firm
This article is focused on creating a system of metrics and its application in a metallurgical firm. Its aim is to highlight the dangers associated with the creation and application of an effective system of metrics. Its objective is also to demonstrate the process (initial steps) in the development of this system in the real family metallurgical firm. In the experimental part an example of causal links among key metrics in the chosen metallurgical firm is presented. Risks associated with the selection of appropriate metrics are presented for discussion
Biological and structural characterization of theMycobacterium smegmatis nitroreductase NfnB, and its rolein benzothiazinone resistance
Tuberculosis is still a leading cause of death in developing
countries, for which there is an urgent need
for new pharmacological agents. The synthesis of
the novel antimycobacterial drug class of benzothiazinones
(BTZs) and the identification of their
cellular target as DprE1 (Rv3790), a component of
the decaprenylphosphoryl-b-D-ribose 2'-epimerase
complex, have been reported recently. Here, we
describe the identification and characterization of a
novel resistance mechanism to BTZ in Mycobacterium
smegmatis. The overexpression of the nitroreductase
NfnB leads to the inactivation of the drug by
reduction of a critical nitro-group to an amino-group.
The direct involvement of NfnB in the inactivation of
the lead compound BTZ043 was demonstrated by
enzymology, microbiological assays and gene knockout
experiments. We also report the crystal structure
of NfnB in complex with the essential cofactor flavin
mononucleotide, and show that a common amino
acid stretch between NfnB and DprE1 is likely to be
essential for the interaction with BTZ. We performed
docking analysis of NfnB-BTZ in order to understand
their interaction and the mechanism of
nitroreduction. Although Mycobacterium tuberculosis
seems to lack nitroreductases able to inactivate
these drugs, our findings are valuable for the design
of new BTZ molecules, which may be more effective
in vivo
Estas son algunas de las habilidades blandas demandadas en Colombia
Este producto forma parte de una serie de infografías de divulgación científica que buscan reseñar algunas de las investigaciones más importantes en las que ha tenido participación la Universidad EAFIT, publicadas en las revistas especializadas más prestigiosas del mund
Side Chain-Modified Benzothiazinone Derivatives with Anti-Mycobacterial Activity
Tuberculosis (TB) is a leading infectious disease with serious antibiotic resistance. The benzothiazinone (BTZ) scaffold PBTZ169 kills Mycobacterium tuberculosis (Mtb) through the inhibition of the essential cell wall enzyme decaprenylphosphoryl-β-D-ribose 2’-oxidase (DprE1). PBTZ169 shows anti-TB potential in animal models and pilot clinical tests. Although highly potent, the BTZ type DprE1 inhibitors in general show extremely low aqueous solubility, which adversely affects the drug-like properties. To improve the compounds physicochemical properties, we generated a series of BTZ analogues. Several optimized compounds had MIC values against Mtb lower than 0.01 µM. The representative compound 37 displays improved solubility and bioavailability compared to the lead compound. Additionally, compound 37 shows Mtb-killing ability in an acute infection mouse model
An ethA-ethR-deficient Mycobacterium bovis BCG mutant displays increased adherence to mammalian cells and greater persistence in vivo, which correlate with altered mycolic acid composition
10.1128/IAI.01332-13Infection and Immunity8251850-1859INFI
Benzothiazinones Are Suicide Inhibitors of Mycobacterial Decaprenylphosphoryl-β-d-ribofuranose 2'-Oxidase DprE1.
Benzothiazinones (BTZs) are antituberculosis drug candidates with nanomolar bactericidal activity against tubercle bacilli. Here we demonstrate that BTZs are suicide substrates of the FAD-dependent decaprenylphosphoryl-β-d-ribofuranose 2'-oxidase DprE1, an enzyme involved in cell-wall biogenesis. BTZs are reduced by DprE1 to an electrophile, which then reacts in a near-quantitative manner with an active-site cysteine of DprE1, thus providing a rationale for the extraordinary potency of BTZs. Mutant DprE1 enzymes from BTZ-resistant strains reduce BTZs to inert metabolites while avoiding covalent inactivation. Our results explain the basis for drug sensitivity and resistance to an exceptionally potent class of antituberculosis agents