COMPARATIVE-STUDIES OF SHEEP LUNG AND LIVER NITROFURANTOIN REDUCTASE

Date

1993-10-01

Author

İşcan, Mesude

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1. Nitrofurantoin reductase which catalyzes the bioactivation of nitrofurantoin was purified to electrophoretic homogenity from sheep liver and lung microsomes, with a yield of 15% and 35%, respectively. The specific activity of both reductases was found to be similar (140 nmol/min/mg protein). 2. The effects of nitrofurantoin and NADPH concentrations, pH, ionic strength, amount of enzyme and reaction period, on the enzyme activity were studied and the optimum conditions for maximum activity of purified fiver and lung nitrofurantoin reductases were determined. 3. The enzyme concentration was found proportional with the square root of the rate of nitrofurantoin reduction up to approximately 15 mug protein/ml and 25 mug protein/ml incubation mixture for liver and lung nitrofurantoin reductases, respectively. 4. The plots of inverse of the nitrofurantoin concentration against the inverse of the square root of the velocity for the reduction of nitrofurantoin by liver and lung enzymes gave K(m) values as 27.78 muM and 32.25 muM, respectively. 5. The purified liver and lung enzymes were also saturated by NADPH at similar concentrations and the K(m) values were calculated as 29.4 muM and 35.5 muM, respectively. 6. The effects of magnesium, nickel, cadmium and copper ions on the nitrofurantoin reductase activity were examined. Magnesium ion was found to have almost no effect, whereas the other ions inhibited the activity of both liver and lung reductases.

Subject Keywords

Immunology, Pharmacology

URI

https://hdl.handle.net/11511/52144

Journal

COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY C-PHARMACOLOGY TOXICOLOGY & ENDOCRINOLOGY

DOI

https://doi.org/10.1016/0742-8413(93)90182-k

Collections

Department of Biology, Article

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Citation Formats

M. İşcan, “COMPARATIVE-STUDIES OF SHEEP LUNG AND LIVER NITROFURANTOIN REDUCTASE,” COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY C-PHARMACOLOGY TOXICOLOGY & ENDOCRINOLOGY, pp. 579–584, 1993, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/52144.