Kinetic analysis of the effects of monovalent cations and divalent metals on the activity of Mycobacterium tuberculosis α-isopropylmalate synthase

2006 ◽  
Vol 451 (2) ◽  
pp. 141-148 ◽  
Author(s):  
Luiz Pedro S. de Carvalho ◽  
John S. Blanchard
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Kinetic Analysis ◽  
Monovalent Cations ◽  
Divalent Metals ◽  
Isopropylmalate Synthase

scholarly journals Development of a Colorimetric Assay and Kinetic Analysis for Mycobacterium tuberculosis D-glucose-1-phosphate Thymidylyltransferase

2011 ◽  
Vol 17 (2) ◽  
pp. 252-257 ◽  
Author(s):  
Shanshan Sha ◽  
Yan Zhou ◽  
Yi Xin ◽  
Yufang Ma
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Kinetic Analysis ◽  
High Throughput Screening ◽  
Initial Velocity ◽  
Colorimetric Assay ◽  
Microtiter Plate ◽  
Kinetic Properties ◽  
Optimal Temperature ◽  
Antituberculosis Drugs ◽  
Optimal Ph

dTDP-L-rhamnose as a sugar donor provides L-rhamnosyl residue in the synthesis of disaccharide linker (D-N-acetylglucosamine-L-rhamnose), the key structure of the Mycobacterium tuberculosis cell wall. Four enzymes are involved in the formation of dTDP-L-rhamnose and D-glucose-1-phosphate thymidylyltransferase (RmlA) catalyzes the first step of D-glucose-1-phosphate and dTTP to dTDP-D-glucose and PPi. The previous studies on RmlA essentiality proved RmlA as a potential target for antituberculosis drugs. However, there has not been a suitable assay for RmlA to screen inhibitors currently. In this study, the authors reported a microtiter plate–based colorimetric assay for RmlA enzyme activity. Using this assay, the kinetic properties of M. tuberculosis RmlA including initial velocity, optimal temperature, optimal pH, the effect of Mg2+, and kinetic parameters were determined. The establishment of the accurate and rapid colorimetric assay and kinetic analysis of M. tuberculosis RmlA will facilitate high-throughput screening of RmlA inhibitors.

scholarly journals Identification of inhibitors against α-Isopropylmalate Synthase of Mycobacterium tuberculosis using docking-MM/PBSA hybrid approach

2017 ◽  
Vol 13 (05) ◽  
pp. 144-148 ◽  
Author(s):  
Preeti Pandey ◽  
◽  
Andrew M. Lynn ◽  
Pradipta Bandyopadhyay ◽  
◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Hybrid Approach ◽  
Isopropylmalate Synthase

Kinetic analysis of Mycobacterium tuberculosis-specific cytokine production by PBMC in adults after BCG vaccination

2005 ◽  
Vol 11 (1) ◽  
pp. 18-23 ◽  
Author(s):  
Shigeki Nabeshima ◽  
Masayuki Murata ◽  
Kouzaburo Yamaji ◽  
Yong Chong ◽  
Jun Hayashi ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Kinetic Analysis ◽  
Cytokine Production ◽  
Bcg Vaccination

scholarly journals Effects of Monovalent Cations on the Sodium-Alanine Interaction in Rabbit Ileum

1970 ◽  
Vol 56 (4) ◽  
pp. 462-490 ◽  
Author(s):  
Raymond A. Frizzell ◽  
Stanley G. Schultz
Keyword(s):  
Kinetic Model ◽  
Kinetic Analysis ◽  
Brush Border ◽  
Monovalent Cations ◽  
Inhibitory Effects ◽  
Rabbit Ileum ◽  
Present Evidence ◽  
Carboxylate Groups ◽  
Competitive Inhibitors ◽  
Anionic Groups

H, K, Rb, and Li inhibit Na-dependent alanine influx across the brush border of rabbit ileum. Kinetic analysis indicates that H and K behave as competitive inhibitors of influx so that increasing the concentration of H or K in the mucosal solution is kinetically indistinguishable from decreasing the Na concentration. In addition the coupling between alanine and Na influxes is markedly reduced at pH 2.5. With the exception of H and Li, none of these monovalent cations significantly affects carrier-mediated alanine influx in the absence of Na indicating that their inhibitory effects are largely restricted to the Na-dependent fraction of influx. Increasing H concentration from 0.03 to 3 mM does not affect influx in the absence of Na but markedly inhibits influx in the presence of Na. Li significantly enhances alanine influx in the absence of Na. Ag, UO2, and La also inhibit the Na-dependent fraction of alanine influx. These findings suggest that anionic groups having a pKa of approximately 4 are involved in the interaction between Na and the alanine-carrier complex; present evidence implicates carboxylate groups however, phosphoryl residues cannot be ruled out. The previously proposed kinetic model for the Na-alanine interaction has been extended to accommodate these effects of H and other monovalent cations. The mechanistic and physiological implications of these findings are discussed.

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