Carboxy-Terminal Region of a Thermostable CITase from Thermoanaerobacter thermocopriae Has the Ability to Produce Long Isomaltooligosaccharides.
Isomaltooligosaccharides (IMOs) have good prebiotic effects, and long IMOs (LIMOs) with a degree of polymerization (DP) of 7 or above show improved effects. However, they are not yet commercially available, and require costly enzymes and processes for production. The Nterminal region of the thermostable Thermoanaerobacter thermocopriae cycloisomaltooligosaccharide glucanotransferase (TtCITase) shows cyclic isomaltooligosaccharide (CI)-producing activity owing to a catalytic domain of glycoside hydrolase (GH) family 66 and carbohydrate-binding module (CBM) 35. In the present study, we elucidated the activity of the C-terminal region of TtCITase (TtCITase-C; Met740-Phe1,559), including a CBM35-like region and the GH family 15 domain. The domain was successfully cloned, expressed, and purified as a single protein with a molecular mass of 115 kDa. TtCITase-C exhibited optimal activity at 40°C and pH 5.5, and retained 100% activity at pH 5.5 after 18-h incubation. TtCITase-C synthesized α-1,6 glucosyl products with over seven degrees of polymerization (DP) by an α-1,6 glucosyl transfer reaction from maltopentaose, isomaltopentaose, or commercialized maltodextrins as substrates. These results indicate that TtCITase-C could be used for the production of α-1,6 glucosyl oligosaccharides with over DP7 (LIMOs) in a more cost-effective manner, without requiring cyclodextran.
['Jeong|Woo Soo|WS|', 'Lee|Yu-Ri|YR|', 'Hong|Seong-Jin|SJ|', 'Choi|Su-Jeong|SJ|', 'Choi|Ji-Ho|JH|', 'Park|Shin-Young|SY|', 'Woo|Eui-Jeon|EJ|', 'Kim|Young Min|YM|', 'Park|Bo-Ram|BR|']
D020134:Catalytic Domain D003001:Cloning, Molecular D004795:Enzyme Stability D004926:Escherichia coli D005964:Glucosyltransferases D006026:Glycoside Hydrolases D006863:Hydrogen-Ion Concentration D008970:Molecular Weight D009844:Oligosaccharides D058105:Polymerization D011994:Recombinant Proteins D016415:Sequence Alignment D020539:Sequence Analysis, Protein D013696:Temperature D046968:Thermoanaerobacter
Thermoanaerobacter thermocopriae long isomaltooligosaccharides Cycloisomaltooligosaccharide glucanotransferase cyclodextran