中文摘要：

目的用不同方法测定蚯蚓组织中一种新型脱氧核糖核酸酶分子量。方法采用凝胶过滤层析法、SDS-PAGE法和基质辅助激光解吸附电离飞行时间质谱法（MALDI-TOF）三种方法测定一种新型蚯蚓脱氧核糖核酸酶（EWDz）的分子量。结果凝胶过滤层析法、SDS-PAGE法和质谱法测定其分子量分别为62．16kD、62．08kD和69．075kD。结论EWDz为单亚基脱氧核糖核酸酶，其分子量在60-70kD。

英文摘要：

Objective To determine relative molecular weight of a novel deoxyribonuclease（EWD2） from the earthworm. Methods Gel filtration chromatography（GFC）, sodium dodecylsulphate-polyacrylamide gel electrophoresis（SDS-PAGE） technique and matrix-assisted laser desorption/ionizationtime of flight mass spectrometry（MALDI-TOF-MS） were used to determine the relative molecular weight, respectively. Results The molecular weights obtained were 62.16 kD（GFC）, 62.08 kD（SDS-PAGE） and 69.07 kD（MALDI-TOF）, respectively. Conclusion The molecular weight of the novel deoxyribonuclease（EWD2） from earthworm includes only one suhunit, and its molecular weight ranges 60 - 70 kD.