Production of Biological Active Single Chain Bovine LH and FSH

Luteinizing hormone as other glycoprotein hormones is characterized by a heterodimeric structure composed a common α-subunit noncovalently linked to a specific β-subunit. The correct conformation of the heterodimer is important for efficient secretion, hormonal-specific post-translational modifications, receptor binding and signal transduction. To determine whether αand βsubunits can be synthesized as a single polypeptide chain (tethered-bLH and -bFSH) and also display biological activities, the tetheredbLH and -bFSH molecules were constructed and transfected into chinese hamster ovary (CHO-K1) cells. LH and FSH activities were assayed by using the human embryonic kidney (HEK) 293 cells expressing rat LH and FSH receptor genes. The tethered-bLH and bFSH proteins were efficiently secreted and showed a similar activity to the dimeric bovine LH and FSH α/β wild type and native purified from bovine pituitary. The tethered-molecules can be permit development of potent new analogues that stimulate ovarian development. Taken together, a single-chain analog can also be constructed to include additional hormone-specific bioactive generating potentially efficacious compounds. These data indicate the potentiality of the single chain approach to further investigate structurefunction relationships of LH and FSH. (Asian-Aust. J. Anim. Sci. 2003. Vol 16, No. 4 : 498-503)