Isolated respectively the DNA fragment from the two kinds of pUCm-T/CTSE following digestion with Kpn I and Bgl II and ligated to the pCAT3-Promoter CAT reporter plasmids.

• 将重组中间载体进行Kpn I+Bgl II双酶切，回收野生型及突变型CTSE片段，再与同样双酶切的pCAT3-Promoter报道基因载体进行连接反应构建含CTSE片段的重组报道基因载体表达系统。