抄録
The conformational changes in baker’s yeast alcohol dehydrogenase (ADH) caused by the interaction of the affinity ligand Procion Blue MX-R, is investigated at various pH values in polyethylene glycol/potassium phosphate aqueous two-phase systems (ATPS). The affinity partitioning of ADH is effectively carried out at neutral pH without any damage to the structural conservation. However, the protein becomes unstable at alkaline PH and is further denatured in the presence of Procion Blue MX-R. The oligomeric ADH is completely dissociated to the monomer, and the tertiary structure of the subunits is affected by the interaction of the Blue ligand. Hydrophobic residues such as tryptophan initially buried inside may become accessible to a solvent and make denatured ADH more hydrophobic than in the native state. This affinity ligand promotes partition of the denatured fraction to the top phase, and of the active fraction to the bottom phase, at alkaline pH. The analysis of partitioning behavior in ATPS could be utilized for sensitive detection of the conformational changes in protein structure.
