Abstract: The present invention relates to a method for purifying an erythropoietin analog having a low isoelectric point below 4 by adding an N-linked sugar chain with high purity. In accordance with the present invention, the erythropoietin analog having an isoelectric point below 4, which is an isoform having more sialic acid residues, can be effectively purified via three-step chromatographic processes in short time at lower cost.

Abstract: The present invention relates to an expression vector for animal cells, comprising: (a) CSP-B (Cytotoxic Serine Protease-B) 5?-SAR (Scaffold or Matrix Attachment Region); (b) a promoter operable in animal cells; and (c) a polyadenylation sequence, and to a method for producing recombinant proteins using same. The vector of the present invention includes CSP-B 5?-SAR, and thus has the effect of overcoming the inhibition of gene expression according to the position of a foreign gene introduced into an animal cell, and significantly improving the expression rate of a target protein. The vector of the present invention effectively expresses recombinant proteins for drugs or antibodies in animal cells. The vector of the present invention and the method for producing recombinant proteins using same may be very usefully applied to the industrial mass production of drugs.

Abstract: The present invention relates to a method for purifying an erythropoietin analog having a low isoelectric point below 4 by adding an N-linked sugar chain with high purity. In accordance with the present invention, the erythropoietin analog having an isoelectric point below 4, which is an isoform having more sialic acid residues, can be effectively purified via three-step chromatographic processes in short time at lower cost.

Abstract: The present invention relates to an expression vector for animal cells, comprising: (a) CSP-B (Cytotoxic Serine Protease-B) 5?-SAR (Scaffold or Matrix Attachment Region); (b) a promoter operable in animal cells; and (c) a polyadenylation sequence, and to a method for producing recombinant proteins using same. The vector of the present invention includes CSP-B 5?-SAR, and thus has the effect of overcoming the inhibition of gene expression according to the position of a foreign gene introduced into an animal cell, and significantly improving the expression rate of a target protein. The vector of the present invention effectively expresses recombinant proteins for drugs or antibodies in animal cells. The vector of the present invention and the method for producing recombinant proteins using same may be very usefully applied to the industrial mass production of drugs.