Transglycosylation properties of maltodextrin glucosidase (MalZ) from Escherichia coli and its application for synthesis of a nigerose-containing oligosaccharide.
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.
Song
Kyung-Mo
KM
Center for Agricultural Biomaterials and Department of Food Science and Biotechnology, Seoul National University, Seoul, Republic of Korea.
Shim
Jae-Hoon
JH
Park
Jong-Tae
JT
Kim
Sung-Hee
SH
Kim
Young-Wan
YW
Boos
Winfried
W
Park
Kwan-Hwa
KH
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
D004187:Disaccharides; D029968:Escherichia coli Proteins; D025942:Oligosaccharides, Branched-Chain; C014637:laminaribiose; D006026:Glycoside Hydrolases; C071233:malZ protein, E coli