EXPRESSION AND ACTIVITY ANALYSIS OF THIOREDOXIN (Trx) FROM MARINE COCCOLITHOPHORID EMILIANIA HUXLEYI VIRUS IN PICHIA PASTORIS
海洋球石藻病毒（Coccolithovirus）硫氧还蛋白（Trx）在毕赤酵母（Pichia pastoris）中的表达及其活性分析

Thioredoxin (Trx), a small molecule ubiquitous multifunctional acidic protein, was found to reduce disulfide bonds of protein (convert SOS to 2 SH) and thereby mitigate the allergenicity of food. Emiliania huxleyi virus (EhV) is the first virus containing Trx gene reported. Here the gene of EhV-Trx was amplified from the recombinant plasid of pBS-EhV99B1-Trx by PCR. Ehv-Trx gene was inserted yeast expression vector pPIC9K to construct recombinant expression plasmid pPIC9K-EhV99B1-Trx. After sequencing, the recombinant expression plasmid was transformed into Pichia pastoris GS115 by electroporation method. The recombinant protein EhV99B1-Trx reduction activity was detected. The results showed that: the open-reading frame (ORF) of EhV99B1-Trx encoded a protein of 197 amino acids; the recombinant EhV99B1-Trx was successfully induced expression in P. pastoris GS115 and the target protein molecular mass was about 27.8kDa; as found for other proteins with intramolecular disulfide bonds, insulin were reduced specifically by the recombinant EhV99B1-Trx and the treated product was relatively stable, which indicated that the EhV99B1-Trx, as a new kind of thioredoxin, do have the potential in food safety areas.