Enzymatic synthesis of a 2-O-alpha-D-glucopyranosyl cyclic tetrasaccharide by kojibiose phosphorylase.
The glucosyl transfer reaction of kojibiose phosphorylase (KPase) from Thermoanaerobacter brockii ATCC35047 was examined using cyclo-{-->6)-alpha-d-Glcp-(1-->3)-alpha-d-Glcp-(1-->6)-alpha-d-Glcp-(1-->3)-alpha-d-Glcp-(1-->} (CTS) as an acceptor. KPase produced four transfer products, saccharides 1-4. The structure of a major product, saccharide 4, was 2-O-alpha-d-glucopyranosyl-CTS, cyclo-{-->6)-alpha-d-Glcp-(1-->3)-alpha-d-Glcp-(1-->6)-[alpha-d-Glcp-(1-->2)]-alpha-d-Glcp-(1-->3)-alpha-d-Glcp-(1-->}. The other transfer products, saccharides 1-3, were 2-O-alpha-kojibiosyl-, 2-O-alpha-kojitriosyl-, and 2-O-alpha-kojitetraosyl-CTS, respectively. These results showed that KPase transferred a glucose residue to the C-2 position at the ring glucose residue of CTS. This enzyme also catalyzed the chain-extending reaction of the side chain of 2-O-alpha-d-glycopyranosyl-CTS.
Watanabe
Hikaru
H
Amase Institute, Hayashibara Biochemical Laboratories, Inc., 7-7 Amase minami-machi, Okayama 700-0834, Japan. amaseken@hayashibara.co.jp
Higashiyama
Takanobu
T
Aga
Hajime
H
Nishimoto
Tomoyuki
T
Kubota
Michio
M
Fukuda
Shigeharu
S
Kurimoto
Masashi
M
Tsujisaka
Yoshio
Y
D002240:Carbohydrate Sequence; D003505:Cyclodextrins / Q000737:chemistry*; D004187:Disaccharides / Q000737:chemistry*; D008969:Molecular Sequence Data; D009844:Oligosaccharides / Q000737:chemistry*; D006005:Phosphorylases / Q000737:chemistry* / Q000302:isolation & purification; D046968:Thermoanaerobacter / Q000201:enzymology*
D003505:Cyclodextrins; D004187:Disaccharides; D009844:Oligosaccharides; C421202:cyclo-tetra-glucose; C008237:kojibiose; D006005:Phosphorylases