Recovery of human serum albumin by dual-mode chromatography from the waste stream of Cohn fraction V supernatant

Plasma fractionation industry is by far the largest protein pharmaceutical provider, but there are still some plasma components in its industrial waste liquid that have not been utilized. This study aimed to develop a simple and efficient method for plasma protein recovery from Cohn fraction V supernatant (FVS), an effluent containing about 40% ethanol. A new affinity chromatography medium was synthesized with a fatty acid ligand. When the medium was applied to recovery of human serum albumin (HSA) from FVS at physiological pH7.4, the process was unsuccessful due to substantial decrease in capacity in the presence of high ethanol concentration. Nevertheless, change of pH from 7.4 to 4.2 emerged an improved adsorption capacity. The carboxyl group of the ligand began to act as cationic ion exchange role. Both HSA and α2HS-glycoprotein were adsorbed by the column, but α2HS-glycoprotein could be eluted by increasing pH from 4.2 to 7.4, while HSA was retained by the column and could only be eluted by addition of fatty acid. Therefore, the adsorption of albumin under pH 4.2 is charge-induced affinity adsorption, not simple ion exchange. The so-called dual-mode adsorption depends not only on the chromatographic medium but also on the separated object and environment. HPSEC showed that the purity of recovered HSA was greater than 98%. Circular dichroism and fluorescence spectra were consistent with that of the commercial product. Furthermore, the measurement by isothermal titration calorimetry showed that the separated HSA still maintained the binding activities with the ligands of warfarin and naproxen. It is therefore possible to directly recover high-purity and high-quality human serum albumin from the effluent of plasma fractionation industry by one-step chromatography.