Enzymatic characterizations and activity regulations of N-acetyl-β-D-glucosaminidase from the spermary of Nile tilapia (Oreochromis niloticus)(ENZYMOLOGY, PROTEIN ENGINEERING, AND ENZYME TECHNOLOGY)

スポンサーリンク

概要

• 論文の詳細を見る

• N-Acetyl-β-D-glucosaminidase (NAGase) is proved to be correlated with reproduction of male animals. In this study, enzymatic characterizations of NAGase from spermary of Nile tilapia (Oreochromis niloticus) were investigated in order to further study its reproductive function in fish. Tilapia NAGase was purified to be PAGE homogeneous by the following techniques: (NH_4)_2SO_4 fractionation (40-55%), DEAE-cellulose (DE-32) ion exchange chromatography, Sephadex G-200 gel filtration and DEAE-Sephadex (A-50). The specific activity of the purified enzyme was 4100 U/mg. The enzyme molecular weight was estimated as 118.0 kD. Kinetic studies showed that the hydrolysis of p-nitrophenyl-N-acetyl-β-D-glucosaminide (pNP-NAG) by the enzyme followed Michaelis-Menten kinetics. The Michaelis-Menten constant (K_m) and maximum velocity (V_m) were determined to be 0.67 mM and 23.26 μM/min, respectively. The optimum pH and optimum temperature of the enzyme for hydrolysis of pNP-NAG was to be at pH 5.7 and 55℃, respectively. The enzyme was stable in a pH range from 3.3 to 8.1 at 37℃, and inactive at temperature above 45℃. The enzyme activity was regulated by the following ions in decreasing order: Hg^<2+> > Zn^<2+> > Cu^<2+> > Pb^<2+> > Mn^<2+>. The IC_<50> of Cu^<2+>, Zn^<2+> and Hg^<2+> was 1.23, 0.28, and 0.0027mM, respectively. However, the ions Li^+, Na^+, K^+, Mg^<2+> and Ca^<2+> had almost no influence on enzyme activity. In conclusion, the enzymatic characterizations of NAGase from tilapia were special to the other animals, which were correlated with its living habit; besides, CuSO_4 and ZnSO_4 should used very carefully as insecticides in tilapia cultivation since they both had strong regulations on the enzyme.

• 公益社団法人日本生物工学会の論文

著者

• Chen Qing-Xi

  School of Life Sciences, Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, Xiamen University

• Zhang Wei-Ni

  University Key Lab for Integrated Chinese Traditional and Western Veterinary Medicine and Animal Healthcare in Fujian Province, Fujian Agriculture and Forestry University

• Bai Ding-Ping

  University Key Lab for Integrated Chinese Traditional and Western Veterinary Medicine and Animal Healthcare in Fujian Province, Fujian Agriculture and Forestry University

• Hu Chong-Wei

  University Key Lab for Integrated Chinese Traditional and Western Veterinary Medicine and Animal Healthcare in Fujian Province, Fujian Agriculture and Forestry University

• Huang Yi-Fan

  University Key Lab for Integrated Chinese Traditional and Western Veterinary Medicine and Animal Healthcare in Fujian Province, Fujian Agriculture and Forestry University

• Huang Xiao-Hong

  University Key Lab for Integrated Chinese Traditional and Western Veterinary Medicine and Animal Healthcare in Fujian Province, Fujian Agriculture and Forestry University

• Chen Qing-Xi

  School of Life Sciences, Xiamen University

関連論文

• Inhibitory kinetics of DABT and DABPT as novel tyrosinase inhibitors(ENZYMOLOGY, PROTEIN ENGINEERING, AND ENZYME TECHNOLOGY)
• Enzymatic characterizations and activity regulations of N-acetyl-β-D-glucosaminidase from the spermary of Nile tilapia (Oreochromis niloticus)(ENZYMOLOGY, PROTEIN ENGINEERING, AND ENZYME TECHNOLOGY)

スポンサーリンク