摘要
Cecropin AD 是由Cecropin A的N 端111 位氨基酸残基和Cecropin D 的C 端1237 位氨基酸残基构成的一个杂合肽,抗菌活性高于天然抗菌肽。根据Cecropin AD 的氨基酸序列,以酵母偏爱密码设计了Cecropin AD 基因,全长140bp 。采用基因片段化学合成结合PCR 法合成Cecropin AD 基因。合成的Cecropin AD 基因克隆到pCRTM21 上,进行DNA 序列测定,证实合成的Cecropin AD 基因的DNA 序列与设计序列完全一致。将Cecropin 基因定向克隆到大肠杆菌酵母穿梭质粒pCLWA2 的Bam HI和Sal Ⅰ位点上,构建成含Cecropin 基因的重组质粒pCAD,将重组质粒转化入宿主酵母AB103 ,以大肠杆菌K12D31 为指示菌,用活性蛋白酸性PAGE 法测定,具有抑菌活性,表明Cecropin 基因在酵母中获得表达。
Cecropin ADisa hybrid peptidethatexhibitsgreaterantibacterialactivitythanthe naturalCecropinsanditisconsistof1 11aminoacidresiduesinthe N endofcecropin Aand 12 37 aminoacidresiduesinthe C endof Cecropin D.Basedontheamino acidsequenceofCecropin AD, Cecropin ADgene was designed accordingtothe coden usageofyeast.The designed gene was140 bp in size synthesized bythe combination ofoligo deoxynucletidessynthesisand PCRmethod.The PCRproduct wasclonedintothe pCRTM2.1 vector.Thesynthetic gene was provedto be correctby therestriction patten andthe DNAsequenceanalysis.Thesynthetic Cecropin ADgene wasinserted intothe E.coli yeastshuttle plasmid pCLWA2 which contains an α factor promoterleader system . The recombinantplasimid wastransferredinto yeast host AB103.Using E.coli K12D31 asindicator strain ,theexpressed productdisplayed antibacterialactivity bytestofacidic PAGE.
出处
《蚕业科学》
CAS
CSCD
1999年第3期175-180,共6页
ACTA SERICOLOGICA SINICA
基金
广东省自然科学基金