Purification and characterization of endo-polygalacturonase from white-rot fungus Lentinula edodes

Abstract

We purified and characterized the polygalacturonase LePG28A from white-rot fungus Lentinula edodes. LePG28A had endo-type polygalacturonase activity, with maximum activity at 70℃ and pH 4.0. In acetate buffer, the enzyme showed activity against sodium polygalacturonate and polygalacturonic acid, but did not degrade calcium polygalacturonate gel. Pectic substances of the wood cell wall are cross-linked by calcium ions, indicating that LePG28A cannot degrade this calcium polygalacturonate gel directly. On the other hand, LePG28A disintegrated calcium polygalacturonate gel in oxalate buffer. This suggests that the enzyme showed synergistic action with oxalic acid in the degradation of calcium polygalacturonate gel. Therefore, oxalic acid has a role in the chelating of calcium ions from pectic substrates.