A Kinetic Study of an Extracellular Dextrin Dextranase from Acetobacter capsulatum ATCC 11894.

Suzuki Masayuki, Unno Takehiro, Okada Gentaro

doi:10.5458/jag.47.27

The kinetic studies of an extracellular dextrin dextranase (DDase, EC 2.4.1.2) from Acetobacter capsulatum ATCC 11894 were performed by using a series of maltooligosaccharides (DP= 3-7) and short-chain amylose (DP=17.3). The kinetic parameters (Km, Vmax, Ki and Ks) of DDase for the above maltodextrins were first determined. The conversion rates from various maltodextrins into dextran increased with the increase in the DP number of donor substrates. The maximum yield of product dextran reached about 74% by using short-chain amylose as the substrate. The dextran synthesis reaction by DDase was strongly inhibited by maltose. The mode of inhibition of dextran synthesis by DDase action was mixed. From the inhibition studies of DDase, maltose molecules were definitely able to be glucosyl group acceptors. Therefore, various oligosaccharides were able to be formed from a high concentration of maltose as glucosyl group acceptors. The oligosaccharides formed were separated, purified and analyzed by 1H-and 13C-NMR. The chemical structures of the purified glucooligosaccharides were identified as 4-O-α-isomaltosyl-D-glucose, 4-O-α-isomal-totriosyl-D-glucose, 4-O -α-isomaltotetraosyl-D-glucose, 4-O-α-isomaltopentaosyl-D-glucose and 4-O-α-isomaltohexaosyl-D-glucose.

A Kinetic Study of an Extracellular Dextrin Dextranase from Acetobacter capsulatum ATCC 11894.

Bibliographic Information

Search this article

Description

Journal

Citations (2)*help

References(9)*help

Details 詳細情報について

Export

Report a problem