Novel Malto‐Oligosaccharide‐Producing Amylase AmyAc from Archangium sp. Strain AC19 and Its Catalytic Properties

Abstract

Functional maltooligosaccharides (MOSs) derived from starch have potential applications in the food industry and medicine due to their specific functional properties. In this study, a novel maltose (G2) and maltotriose (G3)-producing amylase AmyAc from Archangium sp. strain AC19 is identified. AmyAc is a protein of 874 amino acids, with an N-terminal signal peptide as well as hydrolase family 13 (GH13) catalytic and C-terminal binding modules. However, its sequence is not highly similar to any of the reported starch hydrolases. The V max of AmyAc is 124 µmol min −1 mg −1 under optimal conditions of 50°C and pH 7.0. AmyAc catalyzes the conversion of MOSs and soluble starch into maltose and maltotriose as the end-product with more than 85% purity. AmyAc initially produces G2, G3, and oligosaccharides with even units, following by the release of G2 and oligosaccharides with odd units during later stages of hydrolysis, indicating a distinct catalytic selectivity. The production of MOSs from starch by AmyAc is of significant interest due to potential applications in starch processing.

Identification and Characterization of Novel Malto-Oligosaccharide-Forming Amylase AmyCf from Cystobacter sp. Strain CF23

“…In our previous studies, maltohexaose-forming α-amylase AmyM [ 7 ], α-amylase AmyC [ 32 ], maltogenic amylase CoMA [ 9 ] and G2 + G3-producing amylase AmyAc [ 33 ] have been identified from myxobacteria Corallococcus and Archangium . AmyCf from Cystobacter shares low sequence identity (<30%) with these enzymes except for AmyM (42%), and AmyCf is the first identified α-amylase from Cystobacter .…”

“…Otherwise, no hydrolytic or glucanotransferase activity was observed from G4, G5 and G6 ( Figure 5 c), indicating the strict substrate selectivity of AmyCf. In our previous study, we identified that AmyAc from Archangium hydrolyzes G4 and G5 into G2 + G2 and G2 + G3, respectively, resulting the accumulation of G2 and G3 as the main products [ 33 ]. No action of AmyCf toward G5 and G6 indicates that AmyCf may bind starch chains with DP values more than 9, resulting in the production of G2, G3, and G4.…”

Heterologous Expression and Characterization of a Novel Mesophilic Maltogenic α-Amylase AmyFlA from Flavobacterium sp. NAU1659

“…The amylase AmyAc from Archangium sp. Strain AC19 also has maximum hydrolytic activity on soluble starch, however, it has low hydrolytic activity on wheat starch and corn starch, its activity decreased by 67% and 84%, respectively, compared to that on soluble starch (22).…”