摘要
目的:设计能特异性切割人癌基因c-erbB-2 mRNA的核酶(ribozyme).方法:根据Symons的“锤头结构”,以人癌基因c-erbB-2 mRNA为靶RNA,用计算机对其可能为核酶切割的位点进行分析以寻找最佳切点;对底物及核酶的二级结构进行预测.结果:c-erbB-2mRNA第2428～2776位和第2820～3004位之间的二级结构相对稳定,是重要的生物学功能区,因而也是核酶理想的攻击区域.该区第2438,2477,2751位是核酶的最佳切割位点.针对这三个位点设计了三个核酶并分别命名为RZ1,RZ2,RZ3.计算机模拟显示,它们均能与底物切点两翼碱基结合而形成锤头状结构.通过计算机基因库检索,在已知人基因中,其它基因的mRNA均不含有上述三个核酶切点两翼碱基的同源序列.结论:并非所有的GUX或CUX均可作为核酶的理想切割位点,c-erbB-2mRNA上第2438,2477,2751位可能是核酶的最佳切割位点.
Objective:To design the ribozymes which may cleave the mRNA of human c-erbB-2 oncogene. Methods: The c-erbB-2 mRNA was taken as the target RNA. Ribozymes were designed according to the 'hammerhead structure' described by Symons. Computer was used to analyze the possible secondary cleavage sites on c-erbB-2 mRNA and to predict the secondary structures of substrate and ribozymes. Results: The secondary structures of c-erbB-2 mRNA from nt 2428 to nt 2776 and nt 2820 to nt 3004 were relatively stable. The two regions were of important biological function and were the ideal attacking regions for ribozymes. Three ribozymes targeting the nt 2438, nt 2477 and nt 2751 on the c-erbB-2 mRNA were designed and were named RZ1, RZ2 and RZ3 respectively. The hammerhead structures composed of ribozymes and targeting mRNA could be formed by computer imitation. No analogous sequence of substrate which combined with ribozyme was found in the mRNA of other genes in known human Gen Bank through computer probe. Conclusion: Not all GUX or CUX could be taken as the cleavage site of ribozyme. The nt 2438, nt 2477 and nt 2751 on the c-erbB-2 mRNA are the most ideal attacking sites for ribozymes.
出处
《第四军医大学学报》
1997年第1期6-6,共1页
Journal of the Fourth Military Medical University
基金
国家自然科学基金资助课题No.39500066
