Solubilization and Separation of Uridine Diphospho-d-glucose: beta-(1 --> 4) Glucan and Uridine Diphospho-d-glucose:beta-(1 --> 3) Glucan Glucosyltransferases from Coleoptiles of Avena sativa

The particulate glucan synthetase preparation isolated from a homogenate of oat coleoptiles at 4 C lost 65% of its original activity after 1 day when the UDP-d-glucose substrate concentration was 5 × 10⁻⁷m to 1.0 × 10⁻⁶m. Storage of the particulate enzyme at −20 C or in liquid nitrogen did not prevent the enzyme from losing its activity. Incorporation of 0.5% hovine serum albumin into the medium stabilized the particulate enzyme at 0 C for 6 days and for at least 2 weeks in liquid nitrogen.