Abstract: To construct a vector for promoting the high expression of exogenous protein in Pichia pastoris, the exogenous gene was co-expressed with PDI in the same vector, and the YPS1 gene was inactivated simultaneously. Using pPICZαA as backbone vector, the C and N-terminal nonfunctional area sequence of YPS1 pichia gene was connected to pPICZαA vector, then the recombinant vector pPICZαA-YPSΔ was obtained. When pichia PDI gene sequence was connected to pPICZαA vector, recombinant vector pPICZαA-PDI was produced. Next, PDI expression cassette was gained using PCR method with recombinant vector pPICZαA-PDI as a template. After connecting PDI expression cassette to recombinant vector pPICZαA-YPSΔ, the high expression vector pPICZαA-PDI-YPSΔ was obtained via screening. Finally, the exogenous genes HSA and hGH were introduced to the vector, then converting to Pichia GS115 in order to test the expression of HSA and hGH. The result implied that high expression vector pPICZαA-PDI-YPSΔ was built successfully. The exogenous gene HSA and hGH achieved high expression with this vector. High expression vector pPICZαA-PDI-YPSΔ could be effectively applied to industrial applications.

Key words: YPS1 gene, PDI expression cassette, Pichia pastoris, HAS, hGH