Purification and characterization of three extracellular protopectinases with polygalacturonase activities from trichosporon penicillatum

Abstract

In a culture filtrate of Trichosporon penicillatum B2, which is a γ-ray irradiation mutant induced from T. penicillatum SNO3, we found three kinds of pectin-releasing enzymes, protopectinases SE1, SE2, and SE3, that have endo-polygalacturonase activity. These enzymes were purified to homogeneity with cation-exchange and size exclusion chromatographies. The major PPase in the culture filtrate was PPase SE1, which accounted for 75% of total activities in the culture filtrate, and the two others were 0.15% (PPase SE2) and 0.007% (PPase SE3). Their molecular masses were approximately 41, 41, and 42kDa on SDS–PAGE, respectively. They had similar enzymatic properties but different PPase activity and pH- and thermo-stabilitv. Antibody against PPase S, which is produced by strain SNO3, inhibited the activities of PPase SE1, SE2, and SE3. However PPase SE1 was completely inhibited by treatment with the anti-PPase S antibody, but the activities of PPases SE2 and SE3 remained at 20 and 50% of the original activity, respectively. © 1996, Taylor & Francis Group, LLC. All rights reserved.