牛乳铁蛋白肽基因LfcinB的合成及真核表达载体的构建

根据APD抗菌肽数据库报道的牛乳铁蛋白肽LfcinB氨基酸序列，合成编码LfcinB基因的2条互补的寡核苷酸链，退火后在5′端和3′端分别形成含有BamH I和Xho I位点粘性末端的双链DNA。真核表达载体pcDNA3.1（+）经BamH I 和Xho I限制性内切酶双酶切处理后与合成的LfcinB基因进行连接，连接产物转化E.coli DH5α感受态细胞，提取质粒DNA进行测序。测序结果显示，牛乳铁蛋白肽LfcinB基因成功克隆到pcDNA3.1（+）真核表达载体中，为进一步表达和抗菌活性研究奠定物质基础。

Synthesis of Bovine Lactoferricin B Gene and Construction of Eukaryotic Expression Vector

Two complementary sense and antisense oligo-nucleotides, encoded bovine lactoferricin B gene (LfcinB), were synthesized based on amino acids sequence of bovine lactoferricin B published in the antimicrobial peptide database (APD). After the sense and antisense oligo-nucleotides annealed, a cohesive BamH I site at 5′terminus and a cohesive Xho I site at 3′terminus were formed. Synthesized LfcinB gene and eukaryotic expression vector pCDNA3.1 (+) digested with BamH I and Xho I restriction endonuclease were ligated, and ligation products were transformed into E.coli DH5α. Plasmid extracted from transformed bacteria were sequenced by Sanger dideoxymethod. Sequencing result indicated the synthesized LfcinB gene was successfully cloned to multiple cloning site of vector pCDNA3.1 (+). This may lay a foundation for expression and antimicrobial activities in future.