Covalently attached complexes purification

A different approach involves the use of ligands covalently attached to PEG, as noted above (8). The ligand/PEG complex is introduced to the broth, where the ligand binds its target complement, a product. PEG and salt are added, the PEG/ligand/-complement complex partitions preferentially to the PEG phase. The complement has been isolated in the PEG phase, whereas its intrinsic distribution would favor the salt phase. The separation/ purification is high where conditions are such that all other materials partition to the salt phase. 

A glycoprotein which has been isolated from the cell walls of baker s yeast was shown to be a D-mannan-protein complex. After immobilization by covalent attachment to macroporous agarose, this was used in the purification of an a-D-mannosidase from jack-bean meal. 

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