Patent ID: 8609370
Filing Date: 2013-12-17
Classification: A61P,C07K,C12P

Abstract:
1. A process for the production of a highly active sialylation form of a target glycoprotein, said highly active sialylation form of said target glycoprotein having a sialylation degree that is lower than that of a reference glycoprotein, yet said highly active sialylation form of said target glycoprotein also having an activity that is higher than that of said reference glycoprotein, wherein said sialylation degree also corresponds to a determined concentration of at least one sialic acid precursor additive, said process comprising: (a) providing a human expression cell line which harbors at least one defect in the sugar nucleotide biosynthetic pathway of sialic acids, said at least one defect being a defect in at least one enzyme selected from the group consisting of UDP-GlcNAc-2-epimerase, N-acetylmannosamine kinase, N-acetylglucosamine kinase, Neu5Ac-9-P-synthetase, Neu5Ac-9-P-phosphatase, CMP-Neu5Ac synthetase and CMP-sialic acid transporter, and said human expression cell line being transfected with a nucleic acid encoding the target glycoprotein; (b) determining a concentration of said at least one sialic acid precursor additive that is able to reconstitute said defect by a process comprising: (c) expressing the highly active sialylation form of said target glycoprotein in said human expression cell line in a medium supplemented with the at least one sialic acid precursor additive at the concentration determined in step (b)(iii).