[Cloning, expression of human keratinocyte growth factor and its purification and identification].

ABSTRACT

To clone KGF-2 gene, get hKGF-2 protein and detemine its activity. The cNDA of human KGF-2 was isolated from fetal lung by RT-PCR and cloned into pBV220 plasmid. The recombinant pBV220-hKGF-2 plasmid was transformed into E. coli (BL21), induced at 42 degrees C for the expression of hKGF-2. Recombinant human KGF-2 was purified from the ultrasonic-treated BL21 by heparin-Sepharose CL-6B treated column chromatography and cation exchange column chromatography. MTT method was used for the determination of its biological activity. SDS-PAGE showed that rhKGF-2 was expressed in E. coli BL21 as soluble protein of approximately 20kD. The rhKGF-2 protein can stimulate the proliferation of NIH3T3 cells significantly from 1 ng/mL to 10 ng/mL. HKGF-2 cDNA wasclned and highly expressed in E. coli BL21 and the purified rhKGF-2 showed the mitogenic activity on NIH3T3 cells.