Purification and properties of polysaccharide depolymerase associated with phage-infected Pseudomonas aeruginosa
Journal of Biological Chemistry
A polysaccharide depolymerase was puritied 1,688-fold from crude lysates produced by the propagation of a specitic bacteriophage in Pseudomonas aeruginosa. Conventional methods of protein fractionation were employed, namely, salting out with ammonium sulfate, Sephadex gel filtration, and high speed centrifugation. The purified depolymerase behaves as a single entity when tested by electrophoresis in acrylamide gel. On the basis of gel filtration data the molecular weight was estimated to be
... 000. Maximal enzymatic activity was found at pH 7.5. Polysaccharide depolymerases have been reported in various phage-infected bacteria (l-3), and recently it was observed that Pseudomonas putida also produces a depolymerase when infected by phage (4). A system consisting of phage-infected Pseudomonas cmuginosa was reported to produce a polysaccharide depolymerase (5), and reaction of this enzyme with polysaccharide resulted in decreased viscosity, as well as in measurable increases in the levels of hexosamines, hexoses, and reducing substances, thereby distinguishing it from other known phageassociated depolymerases. Although a partial purification of the enzyme has been described (5), a substantial purification of the enzyme is necessary in order to clearly characterize the enzyme and thus permit further study of its properties, mechanism of action, and possible role in the virus life cycle. The present article describes the purification of a polysaccharide depolymerase obtained from phage-infected cultures of P. ueruginosa, as well as some of the properties of this enzyme.