杨树菇中一种脱氧核糖核酸酶的纯化及其性质  

Purification and Enzymological Properties of Deoxyriboendonuclease from Agrocybe aegerita

作　　者：祝雯[1] 谢东扬[1] 林奇英[1] 谢联辉[1] 吴祖建[1] 

机构地区：[1]福建农林大学植物病毒研究所福建省植物病毒工程研究中心生物农药与化学生物学教育部重点实验室,福州350002

出　　处：《中国生物制品学杂志》2008年第10期869-872,共4页Chinese Journal of Biologicals

基　　金：福建省科技厅;教育厅资助项目(2007L2002;2006F5014);福建省青年创新基金(2007F3016).

摘　　要：目的分离纯化杨树菇子实体中脱氧核糖核酸酶,并对其性质进行分析。方法通过80%饱和(NH4)2SO4沉淀、Blue Sepharose 6 Fast Flow、DEAE-Sepharose Fast Flow和SP-Sepharose Fast Flow层析方法,从杨树菇子实体中分离纯化一种脱氧核糖核酸酶。SDS-PAGE和活性SDS-PAGE测定相对分子质量,采用琼脂糖凝胶电泳和紫外分光光度法分析其酶学性质,并检测pH、温度、Mg2+和EDTA浓度对酶活性的影响。结果经纯化得到了一种脱氧核糖核酸酶,其相对分子质量为31000。该酶对超螺旋质粒DNA、λDNA、ssDNA和dsDNA均具有降解活性,对dsDNA的降解活性略高于ssDNA,且酶活性依赖于二价金属阳离子。该酶的最适pH值范围为7.5～9.6,50℃时相对酶活性最高。结论从杨树菇子实体中纯化的脱氧核糖核酸酶属于一种非限制性脱氧核糖核酸内切酶。Objective To isolate and purify a deoxyriboendonuclease（DNase） from Agrobcybe aegerita and study its enzymological properties. Methods DNase was purified from Agrobcybe aegerita by 80% saturated ammonium sulfate precipitation as well as Blue Sepharose 6 Fast Flow, DEAE-Sepharose Fast Flow and SP-Sepharose Fast Flow chromatography, then determined for relative molecular mass by SDS-PAGE and active SDS-PAGE and analyzed for enzymological properties by agarose gel electrophoresis and ultraviolet spectrophotometry. The effect of pH value, temperature as well as magnesium ion and EDTA concentrations on activity of the purified DNase were observed. Results A DNase with relative molecular mass of 31 000 was purified. The DNase showed bivalent metal positive ion-dependent degradation activity to supercoil plasmid DNA, λDNA, ssDNA and dsDNA, and the activity to dsDNA was slightly higher than that to ssDNA. The optimal pH value and temperature for the purified DNase were 7.5 - 9.6 and 50℃ respectively. Conclusion The DNase purified from Agrobcybe aegerita was a kind of non-restriction endonuclease.

关 键 词：杨树菇 脱氧核糖核酸酶 纯化 酶学性质 

分 类 号：Q291[生物学—细胞生物学]