中国明对虾血蓝蛋白C末端片段在毕赤酵母中的表达及其抗菌活性

为研究中国明对虾(Fenneropenaeus chinensis)血蓝蛋白C末端(FcHC-C)的抗菌功能,将血蓝蛋白基因FcHC的2个C末端基因片段连接到毕赤酵母表达载体pPIC9K中,构建酵母表达载体pPIC9K/FcHC-C。该载体经SalI酶切后,采用PEG法转化毕赤酵母(Pichia pastoris GS115)。转化子经过PCR鉴定后,阳性克隆通过含有G418的YPD平板筛选,获得高拷贝重组子。重组毕赤酵母利用甲醇诱导表达目的基因。经Tricine-SDS-PAGE和Western blot分析结果表明,利用酵母工程菌成功表达了血蓝蛋白C末端片段(rFcHC-C1和rFcHC-C2)。抑菌活性鉴定实验结果显示,重组蛋白rFcHC-C1和rFcHC-C2作为阴离子抗菌肽具有抗真菌和抗细菌的活性。

Recombinant expression and antimicrobial activity analysis of hemocyanin C-terminal fragments from Fenneropenaeus chinensis in Pichia pastoris

Two C-terminal coding sequences of Fenneropenaeus chinensis hemocyanin FcHC were cloned into the Pichia pastoris expression vector pPIC9K to produce the pPIC9K/FcHC-C yeast expression vectors. The constructed vectors pPIC9K/FcHC-C1 and pPIC9K/FcHC-C2 were linearized by Sal I enzyme, and transformed into P. pastoris GS115 using PEG-mediated transformation method. PCR identified transformants were screened by G418 selected YPD plates. The P. pastoris transfomants of pPIC9K/FcHC-C expressed the two hemocyanin C-terminal gene fragments by methanol induction. The results of Tricine-SDS-PAGE and Western blotting showed that the recombinant FcHC-C1 and FcHC-C2 peptides (rFcHC-C1 and rFcHC-C2) were expressed successfully. An antimicrobial assay showed that rFcHC-C1 and rFcHC-C2 have antifungal and antibacterial activities as anionic AMPs.