Glycoprotein products are over 60% of protein products in the world market. Recently, the emerging market is the recombinant monoclonal antibody products and they are also glycoprotein products. Glycans in glycoproteins play important roles in the act...
Glycoprotein products are over 60% of protein products in the world market. Recently, the emerging market is the recombinant monoclonal antibody products and they are also glycoprotein products. Glycans in glycoproteins play important roles in the activity, pharmacokinetics, and immunogenecity. Although the same cell line is used for manufacturing the glycoprotein products, the glycoforms can be changed easily according to the manufacturing conditions such as cell culture parameters, production scale, and purificatino parameters. In this study, we performed the collaboratory study to prepare the reproducible and standardized SOPs for N-glycan analysis. Also, we prepared the guidelines for "characterization and specification of N-glycan in the glycoprotein products" and "comparability evaluation according to the change of manufacturing process in biological products". N-glycan analysis is performed by glycan struture analysis, monosaccharide composition, and sialic acid content. We established the deglycosylation procedures for each analysis. In the glycan structure analysis, N-glycans can be deglycosylated by an enzyme, PNGase F, or hydrazinolysis. In the protocol with PNGase F, the deglycosylation was efficient when the denaturing buffers are 1.5% SDS, 10% 2-mercaptoethanol or 1% SDS, 3.19% 2-mercaptoethanol, 3.7% EDTA, when N-glycan was purified by PGC(porous graphitized carbon) column or ethanol. In the protocol with hydrazine, the deglycosylation was efficient when the re-N-acetylation buffer was sodium bicarbonate after acid hydrolysis for 5 hours at 95℃. In the protocol of monosacchardie composition with PMP(1-Phenyl-3-methyl-5-pyrazolone) labeling, the acid hydrolysis was efficient when samples were treated with 2N TFA for 4~5 hours at 100℃. The method had linearity in the range of 10~125 ug of monoclonal antibody product and 5~15 ug of erythropoietin product. The method had 16% RSD of precision and 80~120% recovery of accuracy because there are complex sample pretreatment steps including chloroform washing. In the protocol of sialic acid content, the acid hydrolysis was efficient when samples were treated with 0.1N HCl for 1 hours at 80℃. The method had linearity in the range of 50~150 ug of monoclonal antibody product and 5~15 ug of erythropoietin product. The method had 0.6~0.9% RSD of precision and 96~107% recovery of accuracy.