Recent advances in the capillary electrophoresis of recombinant glycoproteins

Highly efficient methods are required to analyze recombinant proteins for c linical use. These proteins generally produced from mammalian expression sy stems are highly glycosylated and consist of a population of glycosylated v ariants (glycoforms). This review presents the different microscale techniq ues of capillary electrophoresis (CE) for analyzing the intact recombinant glycoproteins and for monitoring their bioproduction. Because of several advantages such as simplicity, speed and automation, cap illary zone electrophoresis (CZE) has been generally employed for the routi ne analysis of the glycoform populations of intact glycoproteins. Capillary isoelectric focusing (CIEF) is a powerful method for a charge-based separa tion of the glycoforms. Micellar electrokinetic capillary chromatography (M EKC) represents an alternative method to CZE for the purity control of reco mbinant glycoproteins, while the sodium dodecyl sulfate-capillary gel elect rophoresis (SDS-CGE) with replaceable gel matrices gives an estimation of t he glycoform molecular masses. The results from CIEF and SDS-CGE are compar able to those from the corresponding slab gel techniques. The recent advanc es in the coupling of CZE with mass-spectrometry (MS) offers new perspectiv es not only for precise molecular mass determinations, but also to better u nderstand the mechanisms involved in the CE separation of glycoforms. (C) 1 999 Published by Elsevier Science B.V. All rights reserved.