患红体病凡纳滨对虾肝胰腺NAGase基本性质的改变研究

Changes of Basic Properties of NAGase from the Hepatopancreas of Prawn (L.vannamei) Suffered from Taura Disease

[目的]为虾养殖过程中红体病的诊断和控制提供重要的理论依据。[方法]分别测定健康和患红体病的凡纳滨对虾(Litopenaeus vanname)的肝胰腺N-乙酰-β-D-氨基葡萄糖苷酶(EC3.2.1.52,NAGase)的比活力及其性质差异。[结果]2种来源NAGase的比活力、基本酶学性质等均存在差异。对虾患红体病后,肝胰腺NAGase的比活力和最适温度下降,但催化反应动力学常数Km、Vm值和活化能上升。[结论]该研究表明NAGase与对虾患病可能存在着密切关系。

[Objective]The research aimed to provide important theoretical basis for diagnosis and control of taura disease during breeding prawn.[Method]N-Acetyl-β-D-glucosaminidase（EC 3.2.1.52,NAGase） from the hepatopancreas of prawn in different sources from heath and taura disease were separated and extracted.The changes of activity and basic properties of the enzyme were studied.[Result]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 from different sources varied.The activity of NAGase and the value of the optimum pH were lower after the prawn suffered from taura disease.But the optimum temperature and the kinetics parameters such as the values of Km,Vm and Ea,were higher after the prawn suffered from taura disease.[Conclusion]The study indicates that there are some intimate relationship between NAGase and if the prawn has taura disease.