Purification of A Recombinant Thrombin-like Enzyme, Gloshedobin by Egg Yolk Antibody-Coupled Adsorbents

The gloshedobin, a snake venom thrombin-like enzyme was biosynthesized in the soluble form and purified by egg yolk antibody-coupled adsorbents from E. coli. As His-tag is not favored from the point of view of high-level and soluble expression, we herein constructed a recombinant gloshedobin without His-tag and developed a novel egg yolk antibody (IgY)-immunoaffinity chromatography for its purification in a higher activity yield. The purification process involving Octyl Sepharose FF, IgY-immunoaffinity chromatography and Source Q, yielded 454.7U mg1 protein of interest and 34.8% activity recovery. The anti-gloshedobin IgY was obtained from eggs by injecting diluted gloshedobin into the breast muscle of laying hens and then purified by several steps including 3.5%, 8.5% and 12% polyethylene glycol-6000 precipitation and affinity chromatography using gloshedobin-coupled agarose gel. The obtained IgY was covalently linked to CNBr pre-activated agarose gel, Sepharose 4B FF, to yield immunoaffinity adsorbents. Both immunological and enzymatic activities of the purified enzyme were determined by western-blotting analysis and fibrinogen clotting assay, respectively.