Pectin 3-galactosidase

In tomato pericarp, the loss of pectin-associated galactose appears to occur via at least two mechanisms. One Involves the EDG-medlated release of a galactan-rich pectin, as demonstrated by Pressey (60). Pressey has also shown that a 6-galactosidase from ripe fruit will depolymerize this galactan in vitro (61), representing an EDG-independent means of gaTactose loss. Gross... 

Galactanases (and a- or j3-D-galactosidase), arabinases (and a-L-arabinosidase) and pectinases (polygalacturonase 5/20 species and pectin methyl-esterase 7/20 species [30] have rarely been studied. Amylase was found in almost all species tested by Gessner [30], Cuomo [16] and Rohrmann [20]. 

As their name implies, hydrolysis is the preferred reaction for hydrolases in water under optimal conditions. Some exanq>les in the polysaccharide area include cellulolytic enzymes for biomass conversion (5), proteases for the degradation of guar gum (21), cellulase for viscosity reduction of xanthan gum (21), and P-D-galactosidase for pectin hydrolysis (21). 

A search of the literature indicated that P-D-galactosidase is known to be biologically active towards pectin (8). In fact, P-D-galactosidase is one of the enzymes involved in the ripening process of fruits (8a). Thus, the observed P-D-galactosidase activity is not inconsistent with the literature. 

Case 3. The enzyme is a mixture of several components. It may have one component that can react with a polymer. This is most likely the situation with P-galactosidase and pectin. 

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