PROCESS DESIGN FOR PURIFICATION OF MUSCLE LACTATE-DEHYDROGENASE BY AFFINITY PARTITIONING USING FREE REACTIVE DYES

It was shown that by using free reactive dyes as affinity ligands, lac tate dehydrogenase (LDH) can be purified with affinity partitioning di rectly from rabbit muscle homogenization. The free reactive dyes not b ound to polyethylene glycol (PEG) showed a strong tendency toward the top PEG-rich phase in aqueous two-phase systems, and thus enhanced the affinity partitioning effect. Wide-ranged reactive dyes were screened in terms of their partitioning abilities for LDH. The effects of vari ous parameters on affinity partitioning behavior of LDH, such as phase composition, impurities in raw material, concentration of dyes, pH of the systems, and addition of salts, were studied. The optimized affin ity extraction process has been carried out for the large-scale purifi cation of LDH from rabbit muscle homogenization. The enzyme was recove red with a yield of 81.3% and a purification factor of 7.4. Both PEG a nd dyes were recovered and reused directly without lowering the qualit y of the product.