[Expression of human leukemia inhibitory factor gene in Pichia pastoris]

The 575 bp artificial synthesized human leukemia inhibitory factor (hLIF) gene was cloned into vector pPICZ alpha A and the constructed expression vector pPICZ alpha A-hLIF was linearized by SacI and transformed into Pichia pastoris X-33. After the screening for Mut phenotype and the PCR analysis of the transformants, hLIF gene expressed in Pichia pastoris. SDS-PAGE and Western blot analysis of the culture supernatants showed that hLIF gene could express as 58.5 kD protein with the desired immunogenicity. Density scanning of the SDS-PAGE gel revealed that the targeted protein accounted for 32.8% of the total protein in the supernatants. The expressed products can inhibit the clone formation of murine's teratoma cells.