Galactosylation with Galactosyltransferases and Integrated Cofactor Regeneration

Galactosylation with Galactosyltransferase and Integrated Cofactor Regeneration 

UDP is recycled by pyruvate kinase to give UTP, employing the activated phosphate donor phosphoenol pyruvate (PEP) which gives pyruvate (Pyr) (Fig. 2). 

By employing this integrated cofactor-regenerated approach, N-acetyl lacto-samine can be formed in multigram amounts with native [30] or immobilized enzymes on silica gel [32] or on a polyamide-based carrier [33]. 

In the presence of a-lactalbumin, however, only glucose and cellobiose (Glc)3l-4Glc) [37] are the preferred acceptors. Neither o-mannose, D-allose, D-galactose, o-ribose, nor D-xylose are substrates. Glucuronic acid and a-glucose-1-phosphate (monosaccharides with a negative charge) are also not accepted. 

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Fig. 2. Galactosylation with galactosyltransferase and integrated cofactor regeneration. (Enzymes i phosphoglucomutase, ii UDP-glucose-pyrophosphorylase, iii inorganic pyrophosphorylase, ivUDP-galactose-4-epimerase, V galactosyltransferase, vi pyruvate kinase, vii hexokinase) [31]...

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