UDP-D-glucose 4-epimerase activity of the tissue culture of white poplars (Populus alba L. var. pyramidalis)

Abstract

The presence of UDP-D-glucose 4-epimerase (EC 5.1.3.2) in the culture tissue of white poplar was evidenced. As found, the partially purified enzyme preparation contained UDP-D-glucose glucosyltransferase, UDP-D-galactose galactosyltransferase and non-specific enzymes able to cleave the uridine-diphosphate saccharides into the appropriate hexose monophosphates. The activity change of UDP-D-glucose 4-epimerase in tissue culture cells during the growth was in accord with changes in D-galactose content in cell walls and indicated the possibility to regulate the formation of polysaccharides containing D-galactose at the level of production of UDP-D-galactose in cells.