earticle

영어

Most therapeutic proteins are glycosylated. These functional sugar moieties of proteins, so called glycan, are very important factor which determine pharmacological properties of the protein therapeutics. Therefore, regulation of glycosylation of protein is significant for producing Biotherapeutics. Polylactosamine is a basic structure of glycans having repeated structure of N-acetyllactosamine(LacNAc) which composed of Galactose(Gal) and N-acetylglucosamine(GlcNAc). Erythropoietin(EPO) is a heavily glycosylated cytokine that stimulates hematopoiesis. The EPO is known to be cleared much faster in vivo when containing polylactosamine than without it and in vivo activity of the EPO is proportional to the level of GlcNAc branching of its N-glycan. In this point of view, we tried to decrease the expression of polylactosamine structure as well as increase the ratio of the tetra antennary-structure on EPO as a model glycoprotein. We inhibited polylactosamine biosynthesis of recombinant human EPO in CHO cells by using siRNA which targets β3gnt2 gene that synthesize β1,4-Gal and β1,3-GlcNAc branch. As a result, the polylactosamine ratio of EPO was decreased to 2% compared with the 21% of wild type. In addition, the ratio of tetra-antennary structure was up-regulated to 46% compared with the 32% of wild type. This might be promising result for producing therapeutic glycoproteins with high in-vivo stability and activity.