A flow microcalorimetric method for enzyme activity measurements: Application to dihydrofolate reductase
| Autor: | Robert Gilli, Claudette Briand, Lucas M. Sica, Jean Claude Sari |
|---|---|
| Rok vydání: | 1987 |
| Předmět: |
Isothermal microcalorimetry
Enthalpy Biophysics Calorimetry Biochemistry Dihydrofolate reductase medicine Animals Lung Molecular Biology chemistry.chemical_classification biology Cell Biology Enzyme assay Enzymes Rats Kinetics Tetrahydrofolate Dehydrogenase Enzyme Liver chemistry biology.protein Molecular targets Cattle Methotrexate Sensitivity limit medicine.drug |
| Zdroj: | Analytical Biochemistry. 165:341-348 |
| ISSN: | 0003-2697 |
| DOI: | 10.1016/0003-2697(87)90279-x |
| Popis: | A flow microcalorimetric method was developed for the analysis of enzymatic activities in crude tissue homogenates. It can be applied whenever a heat exchange is involved in an enzymatic reaction. The consequent sensitivity obviously depends on the enthalpy variation observed. Dihydrofolate reductase was chosen as an example; this enzyme is the molecular target of methotrexate, a widely used anticancer agent. This calorimetric method, whose sensitivity limit is 1.48 X 10(-4) units of dihydrofolate reductase per milliliter of reactant medium, allows enzyme activity measurements in tissues with low dihydrofolate reductase levels. A few examples of measurements in animal tissues are given. These measurements are of some interest; indeed, increased activity and increased levels of this enzyme are two of the mechanisms which may explain resistance to methotrexate. |
| Databáze: | OpenAIRE |
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