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Allosteric and Kinetic Properties ofL-Lactate Dehydrogenase fromThermus caldophilusGK24, an Extremely Thermophilic Bacterium
| Content Provider | Scilit |
|---|---|
| Author | Taguchi, Hayao Machida, Masayuki Matsuzawa, Hiroshi Ohta, Takahisa |
| Copyright Year | 1985 |
| Description | We investigated the allosteric and kinetic properties of the heat-stable L-lactate dehydrogenase (EC 1.1.1.27) from Thermus caldophilus GK24. In the absence of an effector, the pyruvate and l-lactate saturation curves for the enzyme were sigmoid. In the presence of 0.2 mM fructose 1,6-bisphosphate, the most potent effector, the substrate saturation curves ceased to show the positive cooperativities. The maximum velocity of pyruvate reduction increased 7-fold on the addition of fructose 1,6-bisphosphate. This fructose 1,6-bisphosphate-dependent enzyme activity was strongly inhibited by high concentrations of the substrate (pyruvate). In contrast, the NADH and NAD$ ^{+}$ saturation curves for the enzyme were hyperbolic independent of fructose 1,6-bisphosphate. Glucose 1,6-bisphosphate, fructose 2,6-bisphosphate and 5-phosphoribosyl 1-pyrophosphate also activated the enzyme to some extent. Inorganic phosphate slightly activated the enzyme, while it was rather inhibitory for the fructose 1,6-bisphosphate-dependent enzyme reaction. Oxamate, an analogue of pyruvate, activated the enzyme and caused the positive cooperativity for pyruvate to disappear. The intracellular concentrations of fructose 1,6-bisphosphate and pyruvate and the kinetic properties of L-lactate dehydrogenase of T. caldophilus Gk24 indicate that the enzyme exhibits the pyruvate reduction activity in concert with glycolysis under allosteric regulation by fructose 1,6-bisphosphate. |
| Related Links | https://www.tandfonline.com/doi/pdf/10.1080/00021369.1985.10866729?needAccess=true |
| Ending Page | 365 |
| Page Count | 7 |
| Starting Page | 359 |
| ISSN | 09168451 |
| e-ISSN | 13476947 |
| DOI | 10.1080/00021369.1985.10866729 |
| Journal | Bioscience, Biotechnology, and Biochemistry |
| Issue Number | 2 |
| Volume Number | 49 |
| Language | English |
| Publisher | Informa UK Limited |
| Publisher Date | 1985-02-01 |
| Access Restriction | Open |
| Subject Keyword | Biochemistry and Molecular Biology Lactate Pyruvate Dehydrogenase Substrate Kinetic Allosteric Extremely Caldophilus Gk24 |
| Content Type | Text |
| Subject | Organic Chemistry Medicine Analytical Chemistry Molecular Biology Biochemistry Applied Microbiology and Biotechnology Biotechnology |
