- 作者： 陳義雄; 羅銅壁
- 作者服務機構： Contribution from the Department of Chemistry, National Taiwan University, Taipei, Taiwan
- 中文摘要： The chromatographically, disc and microzone electrophoretically homogeneous 5’-nucleotidase of Formosan cobra venom was prepared. This enzyme has molecular weight of about 10,000 as estimated by gel filtration and by total amino acid analysis. Maximal activity was exhibited between pH 6.5 and 7.0 in 0.1 M Tris-malonate buffer. Mn++ and Mg++ ions enhance the activity. The maximal enhancement was obtained at the final concentration of 10¯3 M regardless of substrate concentration. Ni++ and Zn++ ions inhibit the activity. It is heat stable up to 50℃ for 2 min but complete inactivation occurs at 80℃. It shows a high specificity for hydrolysis of ribonucleoside-5’-phosphate but shows only 20% and completely inactive to deoxyri-bonucleoside-5’-phosphate and 2’- or 3’-nucleotide, respectively. Apparent Km and Vmax values were also determined for AMP. GMP, UMP and CMP.
- 英文摘要： --
- 中文關鍵字： --
- 英文關鍵字： --
