【摘要】 根据从西非植物Pentadiplandra brazzeanaBaillion果实中分离的甜味蛋白brazzein的成熟区氨基酸序列,采用大肠杆菌(Escherichia coli)偏爱的密码子,人工合成了5对寡聚核苷酸序列,经体外连接和PCR扩增后得到了187 bp的brazzein的编码序列,将该序列插入pET-28a载体构建成重组表达载体pET-Br。将pET-Br转化至大肠杆菌BL-21细胞,诱导表达后得到了与预计相对分子质量相同的蛋白。该蛋白约占细菌可溶性蛋白的18.9%,分离纯化后通过蛋白复性,得到有微甜味的产物。更多还原

【Abstract】 According to the amino acid sequence of Brazzein isolated from the fruit of Pentadiplandra baillion,five pairs of oligonucleotides were synthesized by using Escherichia coli biased codons.After ligating and PCR amplification,187 bp coding region of brazzein was obtained and inserted into plasmid pET-28a.The results of induced expression showed that the molecular weight of the protein was the same as expected,accounting for 18.9% of total soluble protein of the E.coli.The protein after being denatured and renatured bears a lightly sweet taste.更多还原