不同养殖期的凡纳滨对虾外壳膜NAGase基本性质比较  

Comparison of the basic properties of NAGase from the crustaceous membrane of shrimp(Litopenaeus vannamei) in different stages

作　　者：朴顺金[1] 谢晓兰[2] 黄乾生[1] 谢进金[2] 陈清西[1] 

机构地区：[1]厦门大学生命科学学院教育部细胞生物学与肿瘤细胞工程重点实验室,福建厦门361005 [2]福建泉州师范学院化学与生命科学学院,福建泉州362000

出　　处：《台湾海峡》2006年第3期348-352,共5页Journal of Oceanography In Taiwan Strait

基　　金：福建省青年科技人才创新项目(2004J054);福建省教育厅科技计划项目(JA04260)

摘　　要：以不同生长期的凡纳滨对虾(Litopenaeus vannam ei)的外壳为材料,分离提取外壳膜N-乙酰-β-D-氨基葡萄糖苷酶(EC 3.2.1.52,NAGase),测定分析不同生长期的外壳膜NAGase的酶比活力及其性质的变化.结果表明:不同生长期的酶活力、最适温度、催化反应的动力学参数(Km、vm)、活化能等均存在差异.不同生长期酶的最适pH均为5.5.不同生长期的对虾外壳膜NAGase对Cu2+、Zn2+和Hg2+的敏感性也不同.Cu2+对养殖8周对虾外壳膜NAGase的激活作用最为显著,可以使酶活力提高到400%.Zn2+对不同生长期的酶活力均有抑制作用,但对成体对虾酶抑制作用最为显著,可以使酶活力下降80%.Hg2+对各个生长期的酶活力影响效果也不一样,当浓度为0.1 mmol/dm3时,仅对养殖6、8、9周的对虾的酶有激活作用,当Hg2+浓度为1.0mmol/dm3时,五个生长期的虾皮NAGase活力均受到不同程度抑制.N-Acetyl-β-D-glucosaminidase （EC 3.2. 1.52, NAGase） from the crustaceous membrane of shrimp （Litopenaeus vannamei） in different growth stages was separated and extracted. The variations of activity and basic properties of the enzyme were studied. The results showed that the specific activity, optimum temperature and dynamic constants including Km, vm, and Ea for the hydrolysis of pNP-NAG by the enzyme in different growth stages varied, but the optimum pH was all at 5.5. The effects of metal ions on the enzyme showed that the sensitivities to Cu^2＋ , Zn^2＋ and Hg^2＋ of the enzyme in different growth stages were different. Cu^2＋ activated enzyme in shrimps of 8 week-old was the most activity by increment of 400 %. Zn^2＋ could inhibit the enzyme in all growth stages and the effect was the most in matured shrimp by increment of 80% of its activity. The effects of Hg^2＋ on the enzyme in different growth stages were distinct. When concentration of Hg^2＋ reached 0. 1 mmol/dm^3, it could only activate the enzyme of 6, 8 and 9 week-old shrimp. When concentration was at 1.0 mmol/dm^3, it could inhibit the NAGase enzyme at all 5 stages of shrimp growth.

关 键 词：海洋生物 实验研究 凡纳滨对虾 N-乙酰-Β-D-氨基葡萄糖苷酶 性质比较 

分 类 号：Q556.1[生物学—生物化学]