Cloning, Expression, Purification and CD Analysis of Recombinant Human Betatrophin

Betatrophin is a member of the angiopoietin-like (ANGPTL) family that has been implicated in both triglyceride and glucose metabolism. The physiological functions and molecular targets of this protein remain largely unknown; hence, a purified available protein would aid study of the exact role of betatrophin in lipid or glucose metabolism. In this study, we cloned the full-length cDNA of betatrophin from a human liver cDNA library. Betatrophin was expressed in the pET-21b-E. coli Bl21 (DE3) system and purified by immobilized metal-affinity chromatography and ion-exchange chromatography. Circular dichroism spectroscopy revealed α-helix as the major regular secondary structure in recombinant betatrophin. The production method is based on commonly available resources; therefore, it can be readily implemented.