Substrate complexation and aggregation influence the cyclodextrin glycosyltransferase (CGTase) catalyzed synthesis of alkyl glycosides.

Bacillus macerans cyclodextrin glycosyltransferase (CGTase) was used to convert dodecyl-β-maltoside (DDM) to dodecyl-β-maltooctaoside (DDMO) using α-cyclodextrin (α-CD) or starch as glycosyl donors. At 300mM α-CD, varied DDM concentration and 60°C, the reaction obeyed Michaelis-Menten kinetics with a K(m) value of 18mM and a V(max) value of 100U/mg enzyme. However, at 25mM α-CD the reaction rate decreased with increasing DDM concentration (5-50mM), and when the α-CD concentration was varied at fixed DDM concentration an S shaped curve was obtained.

Towards preparative scale steroid hydroxylation with cytochrome P450 monooxygenase CYP106A2.

Cytochrome P450 monooxygenases are of outstanding interest for the synthesis of pharmaceuticals and fine chemicals, due to their ability to hydroxylate C--H bonds mainly in a stereo- and regioselective manner. CYP106A2 from Bacillus megaterium ATCC 13368, one of only a few known bacterial steroid hydroxylases, enables the oxidation of 3-keto-4-ene steroids mainly at position 15. We expressed this enzyme together with the electron-transfer partners bovine adrenodoxin and adrenodoxin reductase in Escherichia coli.

Challenges of steroid biotransformation with human cytochrome P450 monooxygenase CYP21 using resting cells of recombinant Schizosaccharomyces pombe.

Since cytochrome P450 monooxygenases enable the regio- and stereo-selective hydroxylation of C-H bonds, they are of outstanding interest for the synthesis of pharmaceuticals and fine chemicals. Nevertheless, for industrial applications of such enzymes, e.g.