Altered product specificity of a cyclodextrin glycosyltransferase by molecular imprinting with cyclomaltododecaose

✍ Scribed by Jarunee Kaulpiboon; Piamsook Pongsawasdi; Wolfgang Zimmermann

• Book ID: 102372875
• Publisher: John Wiley and Sons
• Year: 2010
• Tongue: English
• Weight: 325 KB
• Volume: 23
• Category: Article
• ISSN: 0952-3499
• DOI: 10.1002/jmr.1015

✦ Synopsis

Cyclodextrin glycosyltransferases (CGTases), members of glycoside hydrolase family 13, catalyze the conversion of amylose to cyclodextrins (CDs), circular a-(1,4)-linked glucopyranose oligosaccharides of different ring sizes. The CD containing 12 a-D-glucopyranose residues was preferentially synthesized by molecular imprinting of CGTase from Paenibacillus sp. A11 with cyclomaltododecaose (CD 12 ) as the template molecule. The imprinted CGTase was stabilized by cross-linking of the derivatized protein. A high proportion of CD 12 and larger CDs was obtained with the imprinted enzyme in an aqueous medium. The molecular imprinted CGTase showed an increased catalytic efficiency of the CD 12 -forming cyclization reaction, while decreased k cat /K m values of the reverse ring-opening reaction were observed. The maximum yield of CD 12 was obtained when the imprinted CGTase was reacted with amylose at 40-C for 30 min. Molecular imprinting proved to be an effective means toward increase in the yield of large-ring CDs of a specific size in the biocatalytic production of these interesting novel host compounds for molecular encapsulations.