食品科学

• 生物工程 • 上一篇    下一篇

鸭肝乳酸脱氢酶的分离纯化及部分性质研究

方 玲,孙才云,唐云明   

  1. 西南大学生命科学学院,淡水鱼类资源与生殖发育教育部重点实验室,三峡库区生态环境教育部重点实验室,重庆 400715
  • 出版日期:2015-08-15 发布日期:2015-08-17

Isolation, Purification and Partial Characterization of Lactate Dehydrogenase from Duck Liver

FANG Ling, SUN Caiyun, TANG Yunming   

  1. Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, Key Laboratory of Freshwater Fish Reproduction and Development, Ministry of Education, School of Life Science, Southwest University, Chongqing 400715, China
  • Online:2015-08-15 Published:2015-08-17

摘要:

新鲜鸭肝经匀浆、磷酸盐缓冲液抽提,乙醇和硫酸铵分级沉淀,DEAE-Sepharose离子交换层析及Superdex-200凝胶过滤层析,获得电泳纯的乳酸脱氢酶。该酶经纯化后酶比活力达到668.82 U/mg,酶活回收率为25.79%,纯化倍数为185.78。该酶的全分子质量约为170.93 kD,亚基分子质量为44.72 kD;最适反应温度为45 ℃,最适pH值为7.4,在25~45 ℃及pH 5~10的范围内稳定性较好;在45 ℃、pH 7.4条件下,测得该酶对底物还原型烟酰胺腺嘌呤二核苷酸(reduced form of nicotinamide-adenine dinucleotid,NADH)的Km值为3.407 μmol/L,对丙酮酸钠的Km值为8.431 μmol/L;草酸、十二烷基硫酸钠(sodium dodecyl sulfate,SDS)、Cu2+、Ag+对该酶的抑制作用最强,Co2+、K+对该酶有双重作用,低浓度时有激活作用,而高浓度时具有抑制酶活性的作用。

关键词: 鸭肝, 乳酸脱氢酶, 分离纯化, 性质

Abstract:

Electrophoresis-purity lactate dehydrogenase (LDH) from duck liver was obtained through the procedures of
homogenization, buffer solution extraction, ethanol precipitation, ammonium sulfate fractionation, DEAE-Sepharose ion
exchange chromatography and Superdex-200 gel ?ltration chromatography. An activity recovery of 25.79% was obtained.
The specific activity of the purified enzyme was 668.82 U/mg with a purification fold of 185.78. The total molecular mass
of the LDH was 170.93 kD consisting of a 44.72 kD subunit. The optimum temperature and pH for the LDH was 45 ℃
and 7.4, respectively. It was stable in the ranges of pH 5–10 and 25–45 ℃. Its Km was 3.407 μmol/L towards NADH and
8.431 μmol/L towards sodium pyruvate. The enzyme activity was be strongly inhibited by SDS, oxalic acid, Cu2+ and Ag+,
but could be enhanced by low concentration of Co2+ and K+.

Key words: duck liver, lactate dehydrogenase, isolation and puri?cation, characterization

中图分类号: