초록
<P><B>Abstract</B></P><P>Productivity and sialylation are two important factors for the production of recombinant glycoproteins in mammalian cell culture. In our previous study, we found that silkworm hemolymph increased the sialylation of recombinant secreted human placental alkaline phosphatase in the insect cells, promoted the transfer of sialic acids onto the glycoprotein oligosaccharides in an in vitro asialofetuin sialylation system, and enhanced recombinant protein production in the Chinese hamster ovary (CHO) cells. These beneficial effects were mainly due to the 30K proteins, which consist of five isoforms. Among the 30K proteins, 30Kc19 was determined to be the major component. In this study, the <I>30Kc19</I> gene was introduced into a CHO cell line producing recombinant human erythropoietin, and its effects on productivity and sialylation were investigated. The transient expression of <I>30Kc19</I> significantly improved the production and sialylation of EPO. A stable cell line containing <I>30Kc19</I> was also established to investigate the effect of <I>30Kc19</I> gene expression. The stable expression of <I>30Kc19</I> increased the production and sialylation by 102.6% and 87.1%, respectively. The enhanced productivity from <I>30Kc19</I> expression is believed to occur because the 30Kc19 protein suppresses the loss of mitochondrial membrane potential and consequently improves the generation of intracellular ATP. In addition, the positive effect of <I>30Kc19</I> expression on sialylation is believed to be due to its ability to maintain sialyltransferase activity. In conclusion, <I>30Kc19</I> expression is a novel approach to improve the production and sialylation of recombinant glycoproteins in CHO cells. Biotechnol. Bioeng. 2011; 108:1634–1642. © 2011 Wiley Periodicals, Inc.</P>