中文摘要：

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6.0×10^4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.

英文摘要：

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.