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ABSTRACT: Obesity is quickly becoming an increasing problem in the developed world. One of the major fundamental causes of obesity and diabetes is mitochondria dysfunction due to faulty metabolic pathways which alter the metabolic substrate flux resulting in the development of these diseases. This paper examines the role of mitochondrial carbonic anhydrase (CA) isozymes in the metabolism of pyruvate, acetate, and succinate when specific isozyme inhibitors are present. Using a sensitive electrochemical approach of wired mitochondria to analytically measure metabolic energy conversion, we determine the resulting metabolic difference after addition of an inhibitory compound. We found that certain sulfonamide analogues displayed broad spectrum inhibition of metabolism, where others only had significant effect on some metabolic pathways. Pyruvate metabolism always displayed the most dramatically affected metabolism by the sulfonamides followed by fatty acid metabolism, and then finally succinate metabolism. This allows for the possibility of using designed sulfonamide analogues to target specific mitochondrial CA isozymes in order to subtly shift metabolism and glucogenesis flux to treat obesity and diabetes.
Bioorganic & medicinal chemistry 07/2012; · 2.82 Impact Factor
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ABSTRACT: In the continual search of new therapeutics, many possible drug candidates are excluded, because they are found to negatively affect mitochondrial function. We have developed an approach for directly, electrochemically assaying mitochondrial metabolic activity as a function of metabolic substrate to determine drug toxicity. By wiring mouse mitochondria to a carbon electrode surface, electrons can be intercepted before they reach Complex IV, the terminal step of electron transport chain. The electrons are rerouted, to a separate electrode of the electrochemical cell, the cathode. This allows for the direct measurement of electrical current and potential of the mitochondria during their oxidation of substrates such as pyruvate and fatty acids when there are different concentrations of drug present. This analytical technique has been shown to reliably assay several classical mitochondrial toxins and exhibits potential for the further development of a drug candidate screening technique, as well as other applications where the quantitative study of mitochondrial dysfunction is important.
The Analyst 07/2011; 136(18):3747-52. · 4.23 Impact Factor
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ABSTRACT: Living cells oxidize a wide variety of fuels by employing enzymes as catalysts for energy conversion. It has been shown that many of these cellular metabolic enzymes exist in sequential and proximal organization within living organisms. This organization, called a metabolon, results in channeling of substrates between enzymes. Biofuel cell researchers have studied multienzyme systems, but they have not investigated the need for proximal three-dimension organization in efficient energy conversion. This work outlines the use of a Krebs cycle metabolon catalyst obtained through the in situ cross-linking of protein within the mitochondria of Saccharomyces cervisea. This cross-linking maintains the integrity of the sequential complexation that exists naturally in the intact biological system. These complexes channel substrate through the enzyme cascade and improve mass transport, thus increasing the current and power density of pyruvate/air enzymatic biofuel cells.
Journal of the American Chemical Society 05/2010; 132(18):6288-9. · 9.91 Impact Factor
