MACROLIGAND D-ALANYL-D-ALANINE-DEXTRAN FOR VANCOMYCIN PURIFICATION - EQUILIBRIUM BINDING STUDY

Water soluble macroligands for vancomycin purification in affinity ult rafiltration have been prepared by coupling the ligand D-alanyl-D-alan ine to dextran activated by tosyl chloride, carbonyldiimidazole, and c hloroformate, respectively. Centrifugal ultrafiltration has been used to study the equilibrium binding of vancomycin for the macroligands. T he affinity binding can be described as Langmuir type adsorption and i s strongly affected by temperature. The binding between vancomycin and macroligand is an unusual endothermic process that binding capacity o f macroligand increases with temperature. Vancomycin has also been suc cessfully purified from fermentation liquor using the macroligand in a centrifugal ultrafiltration device.