The use of cytochrome binding domain protein as a secretory factor to improve the secretion and expression of exogenous genes in Pichia pastoris

Abstract

The invention discloses a use of a cytochrome combined domain protein as a secretion assistant factor in improvement of a secretory expression amount of a foreign gene in pichia pastoris. A cytochrome combined domain protein encoding gene is optimized according to pichia pastoris codon bias and then is fused with a foreign gene to form a fused gene. The fused gene is transformed into pichia pastoris and then is subjected to secretory expression so that a secretory expression amount of the foreign gene in the pichia pastoris is improved obviously. The invention provides a novel use of the cytochrome combined domain protein as a secretion assistant factor, or the cytochrome combined domain protein encoding gene as a secretion assistant gene. In secretion out of pichia pastoris cell, a fused protein expressed by the fused gene containing the cytochrome combined domain protein encoding gene can be cut into a wild type protein and the cytochrome combined domain protein by a KeX2 protease so that an N end of the foreign protein is not added with an additional sequence and physical and chemical properties of a secretory protein are not influenced.

Description

technical field [0001] The present invention relates to the new application of cytochrome binding domain protein and its coding gene, especially relates to the cytochrome binding domain protein and its coding gene as secretory factor or secretory gene to improve the secretion and expression of exogenous gene in Pichia pastoris The new application in the present invention belongs to the application field of cytochrome binding domain protein or its encoding gene. Background technique [0002] Pichia pastoris is a single-celled eukaryotic organism, which has both prokaryotic-like growth characteristics and general eukaryotic cell biology characteristics. It is currently the most successful eukaryotic expression system for exogenous genes. The Pichia pastoris expression system has the advantages of easy operation and culture, a high level of high-density fermentation, stable expression strains, correct translation and post-translational modification, which are closer to higher e...

AI Technical Summary

Problems solved by technology

However, if the target protein cannot be secreted outside the cell, its yield will generally not be higher than 1% of the total cell protein, and the purification of the target protein will become very complicated, and the production cost of the protein will naturally be very high

Therefore, although researchers very much hope to use Pichia pastoris to secrete and express foreign genes efficiently, there are still many genes (especially those genes that are not secreted and expressed in the original bacteria or cells) that cannot be secreted or expressed in Pichia pastoris. Secreted expression is very low, and this problem has also become a key factor limiting the wider application of this expression system

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