No abstract

As the first step in determining whether polysaccharide biosynthetic enzymes can be utilized to improve textural properties in cut vegetables, the glucan synthase II of red beet root microsomes and tissue slices was characterized. In microsomes, maximal rates of glucose incorporation using uridine diphosphate glucose (UDPG) were obtained at pH 7.0 with cellobiose and 5 mM Mg2+. Approximately 30% of the substrate was incorporated into products. Products were partially solubilized by treatment with /3(l-*-3)and d(l-*-4)-glucanases. Subcellular localization experiments demonstrated that the enzyme is located predominantly in the plasma membrane, with lesser levels associated with Golgi-derived vesicles. UDPG was readily incorporated into tissue disks, with the bulk of [14C]glucose associated with the 5000g fraction.