Nucleotides modulate the activity of aspartate racemase of Scapharca broughtonii
| Autor: | Kimihiko Shibata, Takashi Watanabe, Yoshio Kera, Hiroyuki Yoshikawa, Katsumasa Abe, Ryo-hei Yamada, Shouji Takahashi |
|---|---|
| Rok vydání: | 2003 |
| Předmět: |
Purine
Physiology Aspartate racemase Biochemistry chemistry.chemical_compound Crustacea Animals Scapharca broughtonii Nucleotide Binding site Hypoxia Molecular Biology Amino Acid Isomerases chemistry.chemical_classification Binding Sites biology Nucleotides Molecular biology Adenosine Monophosphate Enzyme assay Adenosine Diphosphate Kinetics chemistry biology.protein Pyrimidine Nucleotides Energy Metabolism Nucleoside |
| Zdroj: | Comparative Biochemistry and Physiology Part B: Biochemistry and Molecular Biology. 134:713-719 |
| ISSN: | 1096-4959 |
| DOI: | 10.1016/s1096-4959(03)00031-9 |
| Popis: | The activity of d -aspartate racemase purified from Scapharca broughtonii has been found to depend markedly on some nucleotides. Purine nucleoside monophosphates enhanced the enzyme activity, which was, on the contrary, lowered by purine nucleoside triphosphates and not affected by pyrimidine nucleotides. AMP produced the highest increase of seven-fold in the enzyme activity at 6 mM and a half-maximum increase at approximately 3.8 mM. ATP caused a half-maximum decrease in the activity at approximately 1.4 mM and the remaining activity was lower than 7% at saturating ATP concentrations. AMP and ATP both brought about changes in Vmax and not in Km. Analysis of the effect of AMP and ATP suggests that each of them has its own primary binding site, which is different from the substrate-binding site. In view of these effects of the nucleotides, the roles of the racemase and d -aspartate in energy metabolism under anoxic conditions are discussed. |
| Databáze: | OpenAIRE |
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