Physicochemical Characterization of a Recombinant eCG and Comparative Studies with PMSG Commercial Preparations

Area of Science:

• Veterinary Medicine
• Biotechnology
• Reproductive Biology

Background:

• Equine chorionic gonadotropin (eCG) is crucial for livestock reproductive efficiency.
• Current eCG products are derived from pregnant mare serum gonadotropin (PMSG), with variable purity.
• Recombinant eCG (reCG) presents a potential for standardized, high-quality hormone production.

Purpose of the Study:

• To produce and characterize bioactive recombinant eCG (reCG).
• To compare reCG with purified PMSG, focusing on structural and functional properties.
• To investigate the role of glycosylation in eCG conformation and biological activity.

Main Methods:

• reCG production in CHO-K1 cells and purification via chromatography (HIC, RP-HPLC).
• Characterization using SDS-PAGE, RP-HPLC, SEC-HPLC, fluorescence spectroscopy, and isoelectric focusing.
• Glycosylation analysis using PAD, PNGase F treatment, SDS-PAGE, and WAX-HPLC.

Main Results:

• Purified reCG and PMSG showed slight molecular differences.
• Significant variations in glycosylation patterns were observed between reCG and PMSG.
• Commercial PMSG preparations also exhibited differences in sialic acid content, affecting biological potency.

Conclusions:

• Standardized recombinant protein bioprocessing ensures consistent reCG quality.
• Glycan moieties are critical for eCG conformation, biological activity, and preventing aggregation.
• reCG provides a more reliable and potentially potent alternative for animal reproductive protocols.