Polymer-shielded dye-ligand chromatography of lactate dehydrogenase from porcine muscle in an expanded bed system

Dye-affinity chromatography is a widely used technique in protein purification. It has recently been shown that the efficiency of the chromatography process can be significantly improved by pretreatment of the affinity matrix with certain water soluble polymers such as poly(vinyl pyrrolidone). This technique termed as polymer-shielded, dye-affinity chromatography has been successfully used in packed bed mode at a lab scale for the purification of a number of enzymes. The present work deals with the application of polymer-shielded dye-affinity chromatography in an expanded bed system of Streamline-Cibacron Blue 3GA for the isolation of lactate dehydrogenase from a crude porcine muscle extract. The elution conditions were optimised to obtain an efficient process. A higher recovery of the target enzyme (78%) was obtained from the polymer shielded column as compared to the unshielded column (17%), after low ionic strength elution. The purification factor obtained after chromatography on the polymer shielded column was higher (4.1) than that from unshielded column (1.8).