CHROMATOGRAPHIC-SEPARATION OF RECOMBINANT-HUMAN-ERYTHROPOIETIN ISOFORMS

Erythropoietin (EPO) is the main regulator of erythropoiesis. The huma n glycoprotein hormone is heterogeneous when analyzed by isoelectric f ocusing (IEF). We investigated the possibility of fractionating EPO is oforms using different chromatographic methods. A recombinant human EP O (rhEPO) was obtained from the culture supernatants of a human B-lymp hoblastoid cell line transfected by the human EPO gene. Highly purifie d rhEPO preparations were obtained by immunoaffinity purification. Mor e than fourteen isoforms were observed after IEF. Among the different methods developed for isoform fractionation, the most reproducible res ults were obtained by DEAE-Sephacel chromatography. Seven fractions of decreasing isoelectric point (pI) were obtained. The specific activit y of these fractions measured by an immunoradiometric assay was not eq ually distributed. (C) 1997 Elsevier Science B.V.