Production of Bioactive Salmon Calcitonin from the Nonendocrine Cell Lines COS-7 and CHO

Abstract

Takahashi, K.-I., Y.-C. Liu, N. Hayashi, F. Goto, M. Kato, H. Kawashima and T. Takeuchi. Production of bioactive salmon calcitonin from the nonendocrine cell lines COS-7 and CHO. Peptides 18(3) 439–444, 1997.—To produce bioactive salmon calcitonin from the conventional nonendocrine cell lines, COS-7 and CHO, we devised a salmon calcitonin expression vector by combining the amino-terminus of human calcitonin precursor with a salmon calcitonin sequence, inserting the efficient furin-cleavable processing sequence Arg-X-Arg-X-Lys-Arg before salmon calcitonin, and deleting the carboxyl-terminal extension peptide. This chimeric calcitonin precursor terminates at glycine to easily receive an amidation reaction. COS-7 and CHO produced a high level of bioactive calcitonin by the resorption pit formation assay. Although amidating activity is highly expressed in CHO, but only a little in COS-7 cells, both cells produced a similar level of bioactive calcitonin. Thus, the engineered salmon calcitonin expression vector enables nonendocrine cells even with low amidation activity to produce bioactive calcitonin.