Phosphodiesterase-phosphomonoesterases from Fusarium moniliforme. VI. A modified method of purification and identification of isozymes.

Fusarium phosphodiesterase-phosphomonesterase was purified 1,630-fold with 19% yield from dried powder of the culture medium by a modified method consisting of seven steps. The purified preparation was shown to be devoid of inactive protein by disc electrophoresis. The preparation was homogeneous with respect to size as demonstrated by gel filtration, sodium dodecyl sulfate-polyacrylamide gel electrophoresis and ultracentrifugation. The molecular weights determined by gel filtration on Sephadex G-200 and by sodium dodecyl sulfate-polyacrylamide gel electrophoresis were 106,000 and 100,000, respectively. The sedimentation coefficient at infinite dilution was 5.71 S. Isoelectric focusing of the purified preparation showed the presence of at least four isozymes with isoelectric points of 6.6, 6.3, 6.2, and 5.9.