Substrate complexation and aggregation influence the cyclodextrin glycosyltransferase (CGTase) catalyzed synthesis of alkyl glycosides.
Research output: Contribution to journal › Article
Bacillus macerans cyclodextrin glycosyltransferase (CGTase) was used to convert dodecyl-Î²-maltoside (DDM) to dodecyl-Î²-maltooctaoside (DDMO) using Î±-cyclodextrin (Î±-CD) or starch as glycosyl donors. At 300mM Î±-CD, varied DDM concentration and 60Â°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 Î±-CD the reaction rate decreased with increasing DDM concentration (5-50mM), and when the Î±-CD concentration was varied at fixed DDM concentration an S shaped curve was obtained. The deviations from Michaelis-Menten kinetics were interpreted as being caused by formation of inclusion complexes between Î±-CD and DDM and by micellation of DDM. To achieve a high reaction rate, a high concentration of free Î±-CD is necessary, since Î±-CD in the form of a complex has low reactivity. When starch is used as glycosyl donor in the CGTase catalyzed alkyl glycoside elongation reaction, it is thus important to choose reaction conditions under which the cyclization of starch to Î±-CD is efficient.
|Research areas and keywords||
Subject classification (UKÄ) – MANDATORY
|Journal||Journal of Biotechnology|
|Publication status||Published - 2011|
Related research output
2015, 75 p.
Research output: Thesis › Doctoral Thesis (compilation)