[Isolation, purification and stability of a glutamin(asparagin)ase preparation from Pseudomonas boreopolis 526].

A technique for purification of glutamine asparaginase from Pseudomonas boreopolis 526 is described which provides a 37% yield of the enzyme homogeneous according to electrophoresis in polyacrylamide gel in the presence of sodium dodecyl sulfate. The effect of pH, freezing, thawing and lyophilic drying on the stability of glutamine asparaginase was studied. The enzyme is rather stable at pH 4.8 and 4 degrees C. Lyophilic drying of the homogeneous enzyme without addition of stabilizers resulted in a decrease of its activity an is accompanied by formation of protein conglomerates with molecular weights of 280,000 and 660,000 D. Freezing and thawing decreased the activity of the nature enzyme by 40-50%.