摘要
本文用Hha I DNA甲基化酶为工具酶,制备了不同甲基化水平的Micrococcus IuteusDNA,再用Sephadex G-100凝胶过滤将甲基化了的M.L.DNA分离出来.以园二色差光谱和紫外差光谱等手段检测了不同甲基化水平给M.L.DNA大分子造成的构象变化:随着DNA甲基化水平的的升高,其CD差光谱的值,及紫外差光谱的值均呈增加趋势.这说明DNA大分子的甲基化,使其分子在溶液中变得更为缩拢,而这种缩拢的程度与DNA大分子的甲基化水平呈正相关.
Methylated Micrococcus luteus DNA was prepared with different DNA methylation level by using Hha I DNA methylase and Sephadex G-100 gel filtration. The conformational change of M. L. DNA with different methylation level was measured by CDD and UVD spectra. The values of Δ[θ]270-280 ,-Δ[θ],220-250 and ΔA260 was increased with increasing of M. L. DNA methylation level. These results showed that the M. L. DNA molecule tends to shrink in space by DNA methylation. There is a positive relationship between the shrinking degree of M. L DNA molecule and its methylation level. This study, however, has not observed th B-DNA→Z-DNA transition of M. L DNA molecule.
出处
《生物物理学报》
CAS
CSCD
北大核心
1990年第1期117-123,共7页
Acta Biophysica Sinica
基金
国家自然科学基金(高技术)资助项目
项目号:0388011
