抄録
A method for the purification of endopolygalacturonase III from Coniothyrium diplodiella has been developed. By fractionation with ammonium sulfate and chromatographies on a cation exchanger, Duolite CS-101, and DEAE-cellulose, endopolygalacturonase III was concentrated 25-fold with a yield of 4.5% on the basis of polygalacturonase activity per weight ototal nitrogen.
The purified enzyme was homogeneous on ultracentrifugation and free-boundary electrophoresis. Its sedimentation coefficient was approximately 3.6S. The enzyme was most active in the pH range of 4.0_??_4.5. The enzyme was stable at 40*°C and in the pH range of 5.0_??_6.5, but completely inactivated by heating at 60°C for 10 minutes. The enzyme carried out a random hydrolysis of pectic acid to a mixture of mono-, di- and tri-galacturonic acids as the end products of hydrolysis. The extent of hydrolysis of pectic acid was approximately 54.0%. The ratio of VRu (viscosity-reducing activity) to PGu (saccharifying activity) was 3.00.
