一种蚯蚓脱氧核糖核酸酶分离纯化和性质研究  

Isolation of Deoxyribonuclease Derived from Earthworm and Research of Its Partial Character

作　　者：姚建强[1] 王晓媛[1] 康慧芳[1] 刘志贞[1] 樊慧杰[1] 杨利军[2] 牛勃[1] 

机构地区：[1]山西医科大学生物化学与分子生物学教研室,山西太原030001 [2]山西医科大学科技处,山西太原030001

出　　处：《药物生物技术》2008年第3期185-190,共6页Pharmaceutical Biotechnology

基　　金：国家自然科学基金(30472251);山西省青年科技研究基金(20051044)资助

摘　　要：蚯蚓组织的NaAc抽提液经过热变性、酸变性和丙酮分段沉淀,再经过DEAE-Sepharose和CM-Sepharose层析纯化,从中分离纯化得到一种脱氧核糖核酸酶(EWD2),经SDS-PAGE电泳、基质辅助激光解吸附电离飞行时间质谱法(MALDI-TOF)、毛细管等点聚焦电泳法测定,此DNase的相对分子质量测定为69 100,明显大于已发现的DNaseⅠ和DNaseⅡ。该酶的等电点为6.05,温度稳定性、pH稳定性、激动剂和抑制剂等各项参数,与已发现的各种DNase相比较有明显差别。结果提示,蚯蚓组织中发现的这种脱氧核糖核酸酶具有特殊的酶学性质,可能是一种新型脱氧核糖核酸酶,其作用机理和分类还有待于进一步的研究。The earthworm Eisenia foetida was extracted overnight with NaAc at 4℃, followed by heating-denature, and acid-denature for the extract supernatant. Then a two-step precipitation with freezed acetone（15% and 50%） was performed. The crude protein obtained was purified by DEAE-Sepharose, followed by CM-Sepharose filtration. The purified protein named EWD2 was obtained. The EWD2 is a monomeric protein with a relative molecular weight of 69. 1 kDa estimated by SDS-PAGE, Sephacryl S200 filtration and MALDI-TOF, which is much higher than that of DNase Ⅰ and DNase Ⅱ. The pI of EWD2, measured by Capillary Electrophoresis Isoelectric Focusing （CE-IEF）,was 6. 05. Several parameters of EWD2, for example temperature stability, pH stability, activators and inhibitors are significantly different from those of DNases which have already been found. All of these data indicate that the EWD2 derived from the earthworm has unique enzymatic characteristics, and it is a new kind of deoxyri-bonuclease possibly. Its mechanism of action and classification will be studied in future.

关 键 词：蚯蚓 脱氧核糖核酸酶类 纯化 酶学性质 

分 类 号：Q78[生物学—分子生物学]