Some Characteristics of Formyltetrahydrofolate Synthetase from Pea Seedlings |
| |
Authors: | Kazuo Iwai Noboru Suzuki Shusaku Mizoguchi |
| |
Institution: | Research Institute for Food Science, Kyoto University, Kyoto |
| |
Abstract: | It has been found, that ammonium sulfate is effective not only in stabilizing, but also in stimulating the activity of formyltetrahydrofolate synthetase (E. C. 6, 3. 4. 3) purified approximately 500-fold from pea seedlings. Kinetic studies have indicated that the stimulation by ammonium sulfate is due to the enhancement of the binding of the substrate, formate, with the enzyme. The binding of the another substrate, FAH4, with the enzyme was not affected by the addition of ammonium sulfate. The enzyme activity was inhibited by various sulfhydryl reagents, and the inhibition by PCMB was overcome by the addition of l-cysteine. The inhibition by PCMB was competitive with FAH4, and the Ki value for PCMB was 0.8 × 10?6m. |
| |
Keywords: | |
|
|