title: Transglycosylation properties of maltodextrin glucosidase (MalZ) from Escherichia coli and its application for synthesis of a nigerose-containing oligosaccharide.
abstract: The transglycosylation reaction of maltodextrin glucosidase (MalZ) cloned and purified from Escherichia coli K12 was characterized and applied to the synthesis of branched oligosaccharides. Purified MalZ preferentially catalyzed the hydrolysis of maltodextrin, gamma-cyclodextrin (CD), and cycloamylose (CA). In addition, when the enzyme was incubated with 5% maltotriose (G3), a series of transfer products were produced. The resulting major transfer products, annotated as T1, T2, and T3, were purified and their structures were determined by TLC, MALDI-TOF/MS, (13)C NMR, and enzymatic analysis. T1 was identified as a novel compound, maltosyl alpha-1,3-maltose, whereas T2 and T3 were determined to be isopanose and maltosyl-alpha-1,6-maltose, respectively. These results indicated that MalZ transferred sugar moiety mainly to C-3 or C-6-OH of glucose of the acceptor molecule. To obtain highly concentrated transfer products, the enzyme was reacted with 10% liquefied cornstarch, and then glucose and maltose were removed by immobilized yeast. The T1 content of the resulting reaction mixture reached 9.0%. The mixture of T1 containing a nigerose moiety can have an immunopotentiating effect on the human body and may be a potential functional sugar stuff.
authors.affiliation: Center for Agricultural Biomaterials and Department of Food Science and Biotechnology, Seoul National University, Seoul, Republic of Korea.
authors.forename: Kyung-Mo
authors.initials: KM
authors.lastname: Song
authors.forename: Jae-Hoon
authors.initials: JH
authors.lastname: Shim
authors.forename: Jong-Tae
authors.initials: JT
authors.lastname: Park
authors.forename: Sung-Hee
authors.initials: SH
authors.lastname: Kim
authors.forename: Young-Wan
authors.initials: YW
authors.lastname: Kim
authors.forename: Winfried
authors.initials: W
authors.lastname: Boos
authors.forename: Kwan-Hwa
authors.initials: KH
authors.lastname: Park
mesh_terms: D004187:Disaccharides / Q000737:chemistry*; D004926:Escherichia coli / Q000201:enzymology*; D029968:Escherichia coli Proteins / Q000737:chemistry*; D006026:Glycoside Hydrolases / Q000737:chemistry*; D006031:Glycosylation; D006801:Humans; D025942:Oligosaccharides, Branched-Chain / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology
chemical_list: D004187:Disaccharides; D029968:Escherichia coli Proteins; D025942:Oligosaccharides, Branched-Chain; C014637:laminaribiose; D006026:Glycoside Hydrolases; C071233:malZ protein, E coli