Partial purification of cell wall β‐galactosidases from Cicer arietinum epicotyls. Relationship with cell wall autolytic processes

Abstract

The protein extracted from the cell wall of the epicotyls of Cicer arietinum L. cv. Castellana was separated by ion exchange chromatography in four different fractions with beta-D-galactosidase (EC 3.2.1.23) activity. These were called betaI, betaII, betaIII and betaIV, according to their order of elution.betaII was associated with a particularly high beta-D-glucosidase (EC 3.2.1.21) activity. Gel filtration chromatography of each of the fractions gave further subdivision of fractions betaI and betaIII. Subfractions 1 betaI, 1 betaII and betaIV have glucosidase activity and subfractions 2 betaI and 2 betaIII have galactosidase activity. The studies on the hydrolytic capacity of these fractions and its relationship with the autolytic process seem to show that subfraction 2 betaIII is responsible for autolysis. The release of total and reducing sugars is very similar for autolysis and hydrolysis by 2 betaIII. The sugars released are mainly galactose and, to a lesser extent arabinose and glucose. Galactose is released as a monosaccharide, while arabinose remains associ­ated to a polysaccharide componen! together with glucose and small amounts of galactose.