Specifically increased solubility of enzymes in polyethyleneglycol solutions using polymer-bound triazine dyes.
The enzymes glucose-6-phosphate dehydrogenase (EC 1.1.1.49) and 3-phosphoglycerate kinase (EC 2.7.2.3), present in an extract of Bakers' yeast, are largely kept in solution by minor amounts of polyethylene glycol-bound triazine dyes (Procion yellow HE-3G and Procion olive MX-3G) even when the solution contains such concentrations of polyethylene glycol (12.5% w/w) which normally precipitate the enzymes. The specific prevention from precipitation can be used for purification of enzyme, preferentially in dealing with crude extracts, which has been demonstrated in this work. A 3.4-fold purification of glucose-6-phosphate dehydrogenase has been achieved with good recovery (93%). Further purification has been possible by combining the recovered (enzyme-containing) supernatant liquid with a solution of dextran which generates an aqueous two-phase system. The lower, dextran-containing phase extracts part of the remaining bulk proteins leaving the target enzyme in the upper phase. The advantages of this method for enzyme purification in large scale are discussed.
D004396:Coloring Agents; D004798:Enzymes / Q000302:isolation & purification*; D005954:Glucosephosphate Dehydrogenase / Q000302:isolation & purification; D010735:Phosphoglycerate Kinase / Q000302:isolation & purification; D010751:Phosphopyruvate Hydratase / Q000302:isolation & purification; D011092:Polyethylene Glycols; D012995:Solubility; D014227:Triazines
D004396:Coloring Agents; D004798:Enzymes; D014227:Triazines; D011092:Polyethylene Glycols; D005954:Glucosephosphate Dehydrogenase; D010735:Phosphoglycerate Kinase; D010751:Phosphopyruvate Hydratase