【摘要】 构建了重组质粒ｐＳＶ２ｇｐｔ－ＳＶ４０ｏｒｉ－ａｎｔｉｓｅｎｓｅ－ｒａｓ（简称Ｐ１），利用这一重组体进一步证实了识别序列外ＤＮＡ甲基化对限制性核酸内切酶ＰｖｕⅡ切割活性的抑制作用，并对这一抑制作用进行了定量研究。结果表明：邻近ＰｖｕⅡ识别位，点的ＤＮＡ甲基化可降低ＰｖｕⅡ对该位点酶切活性的７０％左右。更多还原

【Abstract】 The recombinant plasmid pSVZgpt-SV40 ori-antisense-ras (P1)was constructed. Using this plasmid as moldel,it was confirmed that the DNA methylation outside the recognition sequence could inhibit the activity of restriction endonuclease Pvu Ⅱ. Quantitive observation showed that the activity of the Pvu Ⅱ was reduced by 70 percent due to the DNA methylation outside the. recognition sequence.更多还原