Development of a Pilot Technology for the Production of the Recombinant Human Enteropeptidase Light Chain in Soluble and Immobilized Forms

The proteolytic enzyme enteropeptidase (EC 3.4.21.9) is a glycoprotein consisting of a heavy and a light polypeptide chain. The light chain of the enzyme is serine protease whose recombinant variants are used in biotechnology for the cleavage of peptide bonds in hybrid proteins downstream of the specific recognition site DDDDK- or DDDDR-. We have developed a pilot method for producing the recombinant human enteropeptidase light chain containing a cascade of two affine tags. The expression plasmid vector рL-HEP-H6-CBD encoding the hybrid protein was constructed, which contains the sequence of the human enteropeptidase light chain and the metal- and chitin-binding domains. The vector was transformed into the Escherichia coli BL21(DE3) strain, and, after the expression of the hybrid protein HEP-H6-CBD, a relatively simple scheme of renaturation and purification of the enzyme was developed. After the immobilization of the purified preparation on a chitin carrier, the enzyme retained the activity of specific cleavage of substrates for at least six cycles.