1998 Volume 45 Issue 4 Pages 367-372
Cyclodextran glucanotransferase (CITase) synthesized cyclodextrans (CIs) from the substrate dextran. A new assay method of CITase by the convenient measurement of its cyclization reaction was devised by using ODS C18 cartridge (Sep-Pak). By this method, the kinetic parameters of CITase for the cyclization reaction were measured. The Km values for the dextrans T-40, T-110, and T-500 were 7.5, 1.3, and 0.5 mM glucose equivalent, and the Vmax values were 122.3, 72.2, and 48.5 dumol of glucose/min, respectively. Moreover, the hydrolysis reaction of CITase was measured with dextrans and CIs by the reducing sugar assay of the Neocuproine method, and the Km values for the hydrolysis of dextrans were almost comparable with the values for cyclization reaction.