摘要
目的研究溴化乙锭(EB)对BLM解旋酶的生物学特性的影响。方法应用荧光偏振技术研究EB对BLM解旋酶的DNA结合活性与解链活性的影响;应用自由磷检测技术研究EB对BLM解旋酶的ATPase活性的影响;应用紫外吸收光谱法研究EB对BLM解旋酶的构象的影响。结果EB可完全抑制BLM解旋酶的DNA结合活性,当双链DNA与单链DNA作为底物时,Ci值分别为(21.3±0.7)μmol.L-1和(3.3±0.3)μmol.L-1;可完全抑制BLM解旋酶的解链活性,Ci值为(9.0±0.3)μmol.L-1;对BLM解旋酶的ATPase活性有抑制作用,但差异无显著性;可改变BLM解旋酶的构象,最大吸收峰发生红移。结论 EB可以结合BLM解旋酶并改变其构象,抑制其与DNA的结合,从而抑制BLM解旋酶的生物学活性。
Aim To study the effects of ethidium bromide （EB） on biological properties of BLM helicase. Methods Effects of EB on DNA-binding activity and helicase activity of BLM helicase were detected by fluo- rescence polarization; effect on ATPase activity was detected by free phosphorus assay technology; effect on conformation was detected by ultraviolet Absorption spectrum. Results DNA-binding activity of BLM helicase was completely inhibited by EB. Ci was respectively （21.3 ±0.7） I.μmol·L^-1 and （3.3 ±0.3） μmol·L^-1 when dsDNA and ssDNA reacted as thesubstrates; helicase activity was also completely inhibited and Ci was （9.0 ± 0.3 ） μmol·L^-1 ; ATPase activity was inhibited mildly and the disparity was not obvious; conformation of the helicase was changed, and the maximum UV absorption had been shifted. Conclusion EB bound to BLM helicase may change the conformation, inhibit its binding to DNA, and further inhibit the biological activities of the helicase.
出处
《中国药理学通报》
CAS
CSCD
北大核心
2012年第9期1267-1272,共6页
Chinese Pharmacological Bulletin
基金
国家重点基础研究发展计划(973计划)资助项目(No2010CB534912)
教育部博士点基金资助项目(No200806570003)
贵州省国际科技合作计划项目(黔科合外G字[2011]7008号)
贵州省优秀人才省长资金资助项目(No 200822)
贵州大学SRT项目(No 2010024)
