Complete Characterizing of Erythropoietin Glycoforms Using Capillary Zone Electrophoresis Coupled to Mass Spectrometry

Abstract

Erythropoietin (EPO) plays a key role in the production of red blood cells and is currently one of the most important approved drugs. EPO is a glycoprotein of about 30kDa, where the glycosylation has an influence on its lifetime in blood, biological availability and activity. Due to this wide glycoform distribution the direct mass spectral characterization either by ESI or by MALDI failed. Here we show for the first time a method for the accurate mass determination of intact isomeric glycoforms of EPO by ESI-TOF MS, based on prior on-line separation by capillary electrophoresis.