【摘要】 天蚕素A(Cecropin A,CA)是来源于惜古比天蚕(Hyalophoracecropia)的含有37个氨基酸的抗菌肽,在非极性环境中形成α螺旋型结构,具有抗菌活性强、抗菌谱广等特点。为降低天蚕素A对宿主的毒性及提高其表达丰度和稳定性,在序列分析的基础上设计了3条天蚕素A氨基酸序列,分别为CA19、CA36和CA210。根据大肠杆菌密码子的偏爱性分别合成相应的3对寡核苷酸链,并通过重叠PCR方法合成成熟肽CA。将含有CA19、CA36、CA210和CA1～5个拷贝基因的质粒转化大肠杆菌BL21(DE3)和BLR(DE3)PlysS,成功构建了串连融合表达载体,为下一步的抗菌活性及免疫表位的分析打下基础。更多还原

【Abstract】 Cecropin A (CA) is a linear 37-residue-helical antimicrobial peptide produced by Hyalophoracecropia. CA displays strong bacteriolytic activity against a variety of bacteria,fugi,virus and parasite. To reduce the toxic action of CA to host cell and raise the expression level and stability as well,3 stands of amino acid sequence of CA were designed based on sequence analysis, including CA19,CA36,and CA210. Then 3 pairs of oligonucleotide strand corresponding to above 3 stands of amino acid sequence of CA,were synthesized based on the codon favoritism of Esherichia coli. CA mature peptide gene was obtained through overlapping PCR. Vectors containing 1 to 5 repeat units of CA,CA19,C36 and CA210 were constructed respectively. Therefore, the study has provided a foundation for the analysis of antibacterial activity and epitope of CA.更多还原