Intein-Mediated Expression and Purification of an Analog of Glucagon-like Peptide-1 in Escherichia coli

To facilitate expression and purification of an analog of GLP-1 (mGLP-1), an intein system was employed in this study. A recombinant fusion protein, CBD-DnaB-mGLP-1, was constructed and expressed in the form of inclusion body. After refolding, the intein-mediated self-cleavage was triggered by pH and temperature shift. By using chitin beads column followed by single step purification, about 2.58 mg of mGLP-1 with the purity of up to 98% could be obtained from 1 L medium. Tricine-SDS-PAGE, RP-HPLC, and ESI-MS were undertaken to determine the purity and molecular weight of mGLP-1. The glucose-lowering activity of mGLP-1 was also preliminarily determined.