Signal Peptide Optimization to Prevent N-terminal Truncation of Glucagon Like Peptide-1/IgG-Fc Fusion Protein

• Published in: International journal of peptide research and therapeutics 2021-03, Vol.27 (1), p.579-586
• Main Authors: Cao, Chunlai, Wei, Suzhen, Xu, Xukun, Song, Suqin, Lai, Yongjie, Li, Jing
• Format: Article
• Language: English
• Subjects: Animal Anatomy; Batch culture; Biochemistry; Biomedical and Life Sciences; Cell culture; Diabetes mellitus (non-insulin dependent); Fc receptors; Fusion protein; GLP-1 receptor agonists; Glucagon; Histology; Immunoglobulin G; Life Sciences; Molecular Medicine; Morphology; N-Terminus; Peptides; Pharmaceutical Sciences/Technology; Pharmacology/Toxicology; Polymer Sciences
• ISSN: 1573-3149; 1573-3904
• DOI: 10.1007/s10989-020-10112-9

Dulaglutide (glucagon like peptide-1/IgG-Fc fusion protein, GLP-1-Fc) is a long lasting GLP-1 agonist, which consists of two arms of GLP-1 moieties fused to IgG Fc fragment. Dulaglutide is a safe and effective medication for type 2 diabetes. In an attempt to develop a biosimilar version of dulaglutide, we found that up to 75% of GLP-1-Fc displayed N -terminal truncations in one or both GLP-1 arms. We proposed that the N -terminal heterogeneity was caused by mis-cleavage of signal peptide and solved this problem through signal peptide optimization. Murine immunoglobulin kappa light chain signal peptide (KASP) significantly improves GLP-1-Fc N -terminal integrity and homogeneity. 92.8–95.7% of GLP-1-Fc molecules directed by KASP contain intact N -terminus. The productivity of GLP-1-Fc could reach 2.2 g/L in shaking flask fed batch culture. KASP is an optimal signal peptide for GLP-1-Fc expression in Chinese hamster ovary (CHO) cells.