N-GLYCOSYLATION AND O-GLYCOSYLATION MUTEINS OF RECOMBINANT-HUMAN-ERYTHROPOIETIN SECRETED FROM BHK-21-CELLS

Single-site glycomuteins of recombinant human erythropoietin (rhuEpo) were constructed and transiently and stably expressed in BHK-21 cells. The transient expression levels varied among muteins, being highest f or mutein rhuEpo(Gln24) followed by wild-type rhuEpo (rhuEpo(wt)). All other glycomuteins, including rhuEpo(Gln38), rhuEpo(Gln83), rhuEpo(Th r126), and rhuEpo(Gly126), were secreted at lower levels than rhuEpo(w t). Muteins expressed in stable cell lines showed similar differences in expression levels. Also each mutein could be affinity-purified from culture supernatants, and was biologically active in vivo. Based on s ecretion rates from BHK-21 cells, the most potent erythropoietin was r huEpo(Gln24). This mutein is also considered to have biologic activiti es that are superior to rhuEpo(wt). (C) 1995 by The American Society o f Hematology.