Oxidative refolding chromatography: folding of the scorpion toxin Cn5

Abstract
We have made an immobilized and reusable molecular chaperone system for oxidative refolding chromatography. Its three components—GroEL minichaperone (191–345), which can prevent protein aggregation; DsbA, which catalyzes the shuffling and oxidative formation of disulfide bonds; and peptidyl–prolyl isomerase—were immobilized on an agarose gel. The gel was applied to the refolding of denatured and reduced scorpion toxin Cn5. The 66–residue toxin, which has four disulfide bridges and a cis peptidyl–proline bond, had not previously been refolded in reasonable yield. We recovered an 87% yield of protein with 100% biological activity.