Cosubstrate Specificity of the Transgalactosylase of Saccharomyces fragilis

Galactosyl oligosaccharides are produced from lactose by enzyme preparations from yeasts, molds, and bacteria (1, 2). It has been suggested that these compounds are synthesized via a transgalactosylation mechanism in which galactosyl units of lactose are transferred to accepting or cosubstrate molecules (3-5). That the transferring enzyme of Saccharomyces jragilis acts by the transgalactosylation mechanism has now been verified. In addition, a number of saccharides have been tested as cosubstrates for the enzyme with a view to determining its cosubstrate specificity. The latter experiments have resulted in the preparation of several new oligosaccharides.