An Oligogalacturonate Transeliminase from Erwinia aroideal

An oligogalacturonate transeliminase (oligogalacturonate lyase) was isolated from the cell extract of Erwinia aroideae. This enzyme was purified by adsorption on columns of calcium phosphate on cellulose, treatment with Duolite CS-101 and DEAE-cellulose chromatography. It cleaved the first glycosidic linkage from the reducing end of the substrate molecule, the product found in the reaction mixture being 4-deoxy-5-keto-d-fructuronic acid. It attacked preferentially the short-chain uronides. The enzyme preparation showed only a slight activity toward high molecular pectic acid. The pH optimum was at 7.0. Calcium ion had no effect on the enzyme activity. Unsaturated oligogalacturonates were degraded more rapidly than oligogalacturonates having no unsaturated galacturonic acid residue. For this reason it might be appropriate to call this enzyme unsaturated oligogalacturonate transeliminase.