DNA引物酶的提取分离与引物合成活性的研究

EXTRACTION AND PRIMER SYNTHESIS ACTIVITY OF DNA PRIMASE

以小鼠艾氏腹水癌细胞经超声破碎的提取液为材料，依次用ＤＥ５２和Ｐ１１层析柱进行离子线性洗脱，分别在ＫＣｌ浓度为０．１７～０．２ｍｏｌ／Ｌ和０．２５～０．２７ｍｏｌ／Ｌ处ＤＮＡ引物酶被洗脱下来。用大肠杆菌大片段ＤＮＡ多聚酶Ⅰ延长引物法检测ＤＮＡ引物酶比活性为８７５３Ｕ／ｍｇ，酶总获得为２２．１％。

DNA primase was extracted from mouse Ehrlich Ascites Carcinoma cells. The crude enzyme was loaded on DE 52 column and P 11 column sequentially. The primase active fraction was eluted at a KCl concentration of 0.17 mol/L to 0.2 mol/L on DE 52 column and 0.25 to 0.27 mol/L on P 11 column. DNA primase activity was assayed with E coli. DNA polymerase ⅠKlenow fragment extended primers. The specific activity of the enzyme was 8 753 U/mg protein. Different length of primers were synthesized by primase and detected with autoradiograph.