壳聚糖季铵盐-Zn(Ⅱ)催化磷酸双酯与质粒DNA水解动力学  

Kinetics of Catalytic Hydrolysis of Phosphodiester and Plasmid DNA by the Quaternary Ammonium Salt of Chitosan with Zn(Ⅱ)

作　　者：彭英桂[1] 张琦[2] 相艳[1,2] 

机构地区：[1]北京航空航天大学化学与环境学院,北京100191 [2]北京航空航天大学材料科学与工程学院,北京100191

出　　处：《高等学校化学学报》2011年第12期2828-2832,共5页Chemical Journal of Chinese Universities

基　　金：国家自然科学基金(批准号:21073010)资助

摘　　要：采用壳聚糖与缩水甘油三甲基氯化铵反应制备了壳聚糖季铵盐(HTACC),研究了其Zn(Ⅱ)配合物HTACC-Zn(Ⅱ)催化DNA的模拟底物对硝基苯酚磷酸双酯(BNPP)水解的动力学过程及其对质粒DNA的催化裂解.结果表明,HTACC-Zn(Ⅱ)对BNPP的水解反应具有良好的催化活性,其表观一级速率常数可达到6.7×10-6 s-1,为BNPP自发水解时的6.0×104倍;同时,HTACC-Zn(Ⅱ)还能够有效催化质粒DNA(pUC19)的裂解,使DNA分子由超螺旋结构裂解为开环和线型结构.The hydroxypropyl trimethyl ammonium chloride chitosan（HTACC） was synthesized by the reaction of chitosan with glycidyl trimethylammonium chloride.The kinetics of hydrolysis of bis（p-nitrophenyl）phosphate（BNPP） catalyzed by HTACC-Zn（Ⅱ） in Tris-H^＋ buffer was studied and analyzed.In addition,the cleavage of plasmid DNA and the molecular interaction with HTACC-Zn（Ⅱ） were also investigated.The results show that the catalyst has fine catalytic activity to the hydrolysis of phosphodiesters with a first-order rate constant of kobs=6.7×10^-6 s^-1,which is 6.0×10^-4 folds of its spontaneous hydrolysis.Furthermore,the catalyst can cleavage plasmid DNA（pUC19） from supercoiled form to nicked form and/or linear form effectively.

关 键 词：壳聚糖 季铵盐 磷酸双酯 催化水解 DNA裂解 

分 类 号：O643[理学—物理化学]