Watanabe Hikaru, Higashiyama Takanobu, Aga Hajime, Nishimoto Tomoyuki, Kubota Michio, Fukuda Shigeharu, Kurimoto Masashi, Tsujisaka Yoshio
Amase Institute, Hayashibara Biochemical Laboratories, Inc., 7-7 Amase minami-machi, Okayama 700-0834, Japan.
Carbohydr Res. 2005 Feb 28;340(3):449-54. doi: 10.1016/j.carres.2004.12.012.
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.
