Efficient biotransformation and synergetic mechanism of dual-enzyme cascade reaction in nonreducing maltoheptaose synthesis. (June 2021)

• Record Type: Journal Article
• Authors: Zheng, Luhua; Jiang, Bo; Chen, Jingjing; Zhang, Tao; Gu, Xiaohong; Pan, Ying
• Is Part Of: Food bioscience. Volume 41(2021)
• Publication Date: 2021-06
• Subjects: Biotransformation -- Nonreducing maltoheptaose -- Cascade reaction -- Synergetic mechanism; Food -- Biotechnology -- Periodicals; Food -- Research -- Periodicals; Aliments -- Biotecnologia -- Revistes; Aliments -- Investigació -- Revistes; Food -- Biotechnology; Food -- Research; Revistes electròniques; Periodicals; 664.005
• DOI: 10.1016/j.fbio.2021.101066
• Languages: English
• ISSNs: 2212-4292

Abstract

Abstract: Although maltodextrin is an important bulk ingredient in global food industries, its use is affected by its intrinsic disadvantages, including uneven polymerization and high reducibility. Herein, a cascade enzymatic process for preparing nonreducing maltoheptaose (N-G7) from β-cyclodextrin (β-CD) was developed using cyclodextrinase (CDase) and maltooligosyltrehalose synthase (MTSase). Both enzymes showed good synergistic catalytic activity, and the applicability was demonstrated in a one-pot reaction. A hypothetical synergetic mechanism of CDase and MTSase through the analysis of enzyme reaction pathways was proposed. There exists three successive speed-limiting steps in the synthesis of N-G7, namely: opening of β-CD, multi-site hydrolysis of N-G7 by CDase, and hydrolysis of α-1, 1 glycosidic linkage by MTSase. Amongst these, the third speed-limiting step is the most ineffective, and the second speed-limiting step affects the accumulation of N-G7. Fortunately, the MTSase transglycosidic reaction is dominant during the hydrolysis with CDase and is the key to obtain a high yield of N-G7. Highlights: Efficient treatment for synthesising N-G7 from β-CD by dual enzyme cascade reaction. 1.5 U/g-substrate CDase and 15 U/g-substrate MTSase gave maximum N-G7 yield: 77.3%. Three enzyme reactions were studied for hypothetical mechanism of CDase and MTSase. MTSase transglycosidic reaction was more dominant than hyrolyisis by CDase.