Transglucosidase Sucrose Phosphorylase

Whereas /3-fructofuranosidase catalyzes the irreversible64 hydrolytic separation of /3-n-fructofuranosyl from its glucosidic partner in sucrose, transglucosidase (sucrose phosphorylase) accelerates the reversible transfer of the glucose residue of sucrose from fructofuranosyl to another acceptor (c/. equations 3 and 4) ... 

Sucrose phosphorylase can then be regarded as a rather versatile transglucosidase, capable of exchanging glycosidic and ester bonds and of donating D-glucose to a variety of substrates such as ketoses, an aldose, inorganic phosphate and arsenate. 

Fig. 2 Main reactions catalyzed by sucrose-utilizing transglucosidases. The synthesis of a-glucans (Glc) linked through either a-1,6 a-1,3, a-1,4, or a-1,2 osidic linkages depending on the enzyme specificity is obtained by glucansucrases. The formation of a-D-glucose-1-phosphate from orthophosphate is obtained using sucrose-phosphorylases. The mechanism involves a double-inversion at the anomeric center via the formation of a covalent P-D-glucosyl enzyme intermediate...

From various microbial sources have been isolated a sucrose phos-phorylase (sucrose -> orthophosphate transglucosidase) and a maltose phosphorylase (maltose orthophosphate transglucosidase). 

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