Isolation of a Pure Dextranase from Penicillium funiculosum

A dextranase, produced by Penicillium funiculosum , was purified 1,000-fold to yield the enzyme which was demonstrated by gel electrophoresis and electrofocusing to be a homogeneous protein. The purification method included acetone partition, ammonium sulfate fractionation, gel filtration, iron defecation and precipitation, and diethylaminoethyl-cellulose chromatography. The pure enzyme was also obtained by preparative gel electrophoresis. Gel-permeation chromatography indicates a molecular weight of 41,000. An isoelectric p H of 4.6 was established by electrofocusing. A 1-mg amount of the enzyme hydrolyzes a dextran substrate to yield 27,000 isomaltose reducing units in 2 hr. Images