title: Multi-wavelength colorimetric determination of large-ring cyclodextrin content for the cyclization activity of 4-α-glucanotransferase.
abstract: Large-ring cyclodextrins (LR-CDs) have a number of intriguing properties for potential use in pharmaceutical and food industry. To date, no colorimetric method has been reported for LR-CD content quantification. In this study, triple wavelength colorimetry (TWC) and orthogonal-function spectrophotometry (OFS) have been successfully applied to determine ingredient concentrations in a mixture of amylose and LR-CDs. Both TWC and OFS yielded precise amylose content data in good agreement with expected values. For quantification of LR-CD content, OFS provided a higher accuracy than TWC, which resulted in a slight over-determination. As a comparison, single-wavelength colorimetry performed at the corresponding absorption maximum led to a significant over-determination of both amylose and LR-CD contents. The validity of TWC and OFS allowed their application for discriminative detection of the cyclization and total activity of a 4-α-glucanotransferase (4 αGTase) from Thermus aquaticus regarding the synthesis of LR-CDs and the conversion of amylose to small molecules, respectively. High pressure size exclusion chromatography analysis of the post-reaction mixtures following 4 αGTase-catalyzed conversion of amylose revealed the presence of linear malto-oligosaccharides in the LR-CD fraction. By introduction of a correction factor, the interference caused by linear malto-oligosaccharides was eliminated for a more accurate determination of LR-CD cyclization activity.
authors.affiliation: State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, Jiangsu, China; School of Food Science and Technology, Jiangnan University, Wuxi 214122, Jiangsu, China; Synergetic Innovation Center of Food Safety and Nutrition, Jiangnan University, Wuxi 214122, Jiangsu, China. Electronic address: jpwang1984@jiangnan.deu.cn.
authors.forename: Jinpeng
authors.initials: J
authors.lastname: Wang
authors.affiliation: Department of Microbiology and Bioprocess Technology, Institute of Biochemistry, Leipzig University, Johannisallee 21-23, D-04103 Leipzig, Germany.
authors.forename: Ren
authors.initials: R
authors.lastname: Wei
authors.affiliation: State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, Jiangsu, China; Synergetic Innovation Center of Food Safety and Nutrition, Jiangnan University, Wuxi 214122, Jiangsu, China.
authors.forename: Yaoqi
authors.initials: Y
authors.lastname: Tian
authors.affiliation: School of Food Science and Technology, Jiangnan University, Wuxi 214122, Jiangsu, China; Synergetic Innovation Center of Food Safety and Nutrition, Jiangnan University, Wuxi 214122, Jiangsu, China.
authors.forename: Na
authors.initials: N
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, Jiangsu, China; School of Food Science and Technology, Jiangnan University, Wuxi 214122, Jiangsu, China; Synergetic Innovation Center of Food Safety and Nutrition, Jiangnan University, Wuxi 214122, Jiangsu, China.
authors.forename: Xueming
authors.initials: X
authors.lastname: Xu
authors.affiliation: Department of Microbiology and Bioprocess Technology, Institute of Biochemistry, Leipzig University, Johannisallee 21-23, D-04103 Leipzig, Germany. Electronic address: wolfgang.zimmermann@uni-leipzig.de.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Zimmermann
authors.affiliation: State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, Jiangsu, China; School of Food Science and Technology, Jiangnan University, Wuxi 214122, Jiangsu, China; Synergetic Innovation Center of Food Safety and Nutrition, Jiangnan University, Wuxi 214122, Jiangsu, China. Electronic address: jinlab2008@yahoo.com.
authors.forename: Zhengyu
authors.initials: Z
authors.lastname: Jin
mesh_terms: D000688:Amylose / Q000378:metabolism; D002850:Chromatography, Gel; D003124:Colorimetry / Q000379:methods*; D003500:Cyclization; D003505:Cyclodextrins / Q000737:chemistry*; D006004:Glycogen Debranching Enzyme System / Q000378:metabolism*; D009844:Oligosaccharides / Q000378:metabolism*; D013053:Spectrophotometry; D013379:Substrate Specificity; D013824:Thermus / Q000201:enzymology*
chemical_list: D003505:Cyclodextrins; D006004:Glycogen Debranching Enzyme System; D009844:Oligosaccharides; C021705:maltooligosaccharides; D000688:Amylose; C020569:4 alpha-glucanotransferase
keywords: 4-α-Glucanotransferase; Cyclization activity; Large-ring cyclodextrin; Orthogonal-function spectrophotometry; Triple wavelength colorimetry