Endopectate lyase from Erwinia aroideae

Abstract

This chapter describes the assay method and purification procedure of endopectate lyase from Erwinia aroideae . Endopectate lyase activity is determined spectrophotomctrically by measuring the increment of unsaturated compounds at 235 nm absorbance. The end product produced by the enzyme from polygalacturonate consists mainly of unsaturated digalacturonic acid in addition to smaller amounts of unsaturated trigalacturonic acid and saturated monoand digalacturonic acids. The chapter also describes the chemical and physicochemical properties of endopectate lyase. Endopectate lyases are produced by various phytopathogenic microorganisms. In a number of cases, these enzymes have shown to cause extensive cell wall breakdown and maceration, resulting in cell death of infected host tissues. The endopectate lyase purified from the soft rot bacterium E. aroideae has the ability to effectively yield pectic fragments as the reaction products from isolated cell wall preparations. Therefore, purified endopectate lyase is useful in elucidating the chemical structure of pectic polysaccharides of plant cell walls.