Gene amplification and high-level expression of human pro-urokinase cDNA in Chinese hamster ovary cells.
Human Pro-Urokinase (Pro-UK) is expressed in CHO-DHFR- cells at high efficiency by co-transfecting the mouse dhfr gene and Pro-UK cDNA under the control of the SV40 late promoter. After gene co-amplification, the product level could reach 2-3 micrograms/10(6) cells/24 h in the presence of 5 x 10(-6) mol/L MTX, and the levels can be further raised to 3.5-4 micrograms/10(6) cells/24 h by PMA superinduction. The copy number of Pro-UK cDNA in the genomes of host cells is about 200-300 copies/cell. The Western blot analysis shows that the recombinant Pro-UK has similar molecular weight to its natural counterpart, and also the amidolytic activity of the product is determined by S-2444 assay.
Zhang
H Q
HQ
Laboratory of Genetic Engineering, Molecular Genetics Center, Beijing, PRC.
Li
F Z
FZ
Yu
W Y
WY
Li
X Z
XZ
Fang
J M
JM
Fei
E G
EG
Huang
C F
CF
D000818:Animals; D016466:CHO Cells / Q000378:metabolism*; D006224:Cricetinae; D018076:DNA, Complementary / Q000096:biosynthesis* / Q000235:genetics; D004792:Enzyme Precursors / Q000096:biosynthesis* / Q000235:genetics; D005784:Gene Amplification; D006801:Humans; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000235:genetics; D014162:Transfection; D014568:Urokinase-Type Plasminogen Activator / Q000096:biosynthesis* / Q000235:genetics
D018076:DNA, Complementary; D004792:Enzyme Precursors; D011994:Recombinant Proteins; D014568:Urokinase-Type Plasminogen Activator; C067551:saruplase