Development and Application of Cyclodextrin Hydrolyzing Mutant Enzyme Which Hydrolyzes beta- and gamma-CD Selectively

作者：Koo Ye Seul; Ko Dam Seul; Jeong Da Woon; Shim Jae Hoon

来源：Journal of Agricultural and Food Chemistry, 2017, 65(11): 2331-2336.

DOI：10.1021/acs.jafc.7b00269

• cyclodextrins
• alpha-cyclodextrin
• site-directed mutagenesis
• CGTase
• amylase
• bioconversion

Cyclodextrins (CDs) are produced from starch by cyclodextrin glucanotransferase (CGTase), which has cyclization activity. Specifically, alpha-CD is an important biomolecule, as it is a molecular carrier and soluble dietary fiber used in the food industry. Upon inspection of the conserved regions of the glycoside hydrolase (GH) 13 family amylases, the amino acids K232 and H233 of CGTase were identified as playing an important role in enzyme reaction specificity. A novel CD hydrolyzing enzyme, cyclodextrin glycosyl transferase.(CGTase)-alpha, was developed using site-directed mutagenesis at these positions. Action pattern analysis using various substrates revealed that CGTase-alpha was able to hydrolyze beta- and gamma-CD, but not alpha-CD. This selective CD hydrolyzing property was employed to purify a alpha-CD from alpha-CD mixture solution. The alpha-CD that remained after treatment with CGTase-alpha and exotype glucoamylase was purified using hydrophobic interaction chromatography with 99% purity.

• 出版日期2017-3-22