The invention discloses a construction method and application of expression vectors of a
wild type hFIX (human
coagulation factor IX) and three hFIX mutants in
Pichia pastoris. The construction method comprises the following steps: according to a
gene sequence provided by Genebank,
cloning a hFIX full-length cDNA (
complementary deoxyribonucleic acid) sequence from healthy
human liver through a RT-PCR (reverse transcription-
polymerase chain reaction) technology, constructing a
yeast expression
plasmid pPIC9K-hFIX which is used for
Pichia pastoris expression and is fused with a
yeast alpha-factor
signal peptide and a full-length hFIX sequence, transferring the
plasmid into
Pichia pastoris SMD1168, and screening out a high-level expressing
yeast strain; and then, constructing a yeast expression
plasmid pPICAZ-hFIX, designing and constructing three yeast hFIX high-activity mutants on this basis, electrically transferring into
Pichia pastoris SMD1168, and screening out high-level expressing yeast
mutant strains. The coagulation activity of each of the obtained various hFIX yeast expression vectors is higher than that of a standard hFIX. The 50L
pilot fermentation research on the
wild type hFIX (pPIC9K-hFIX) shows that the maximum
protein purification product
secretion expression quantity can be up to 558 mg / L and the purity and coagulation activity are high.