Characterization of an α-glucosidase, HdAgl, from the digestive fluid of Haliotis discus hannai

Abstract

25Previously, we isolated two -amylase isozymes, HdAmy58 and HdAmy82, from 26 the digestive fluid of the Pacific abalone Haliotis discus hannai (Kumagai et al, 2013, 27 Comp. Biochem. Physiol., B 164,[80][81][82][83][84][85][86][87][88]. These enzymes degraded starch producing 28 maltooligosaccharides but not glucose. However, the digestive fluid itself could produce 29 glucose from starch, indicating that the digestive fluid contains -glucosidase-like 30 enzymes together with the -amylases. Thus, in the present study, we isolated this 31 -glucosidase-like enzyme from the digestive fluid and characterized it to some extent. 32Isolation of this enzyme was carried out by ammonium sulfate fractionation followed by

Comprehensive enzymatic analysis of the amylolytic system in the digestive fluid of the sea hare, Aplysia kurodai: Unique properties of two α‐amylases and two α‐glucosidases

“…Recently, a 97‐kDa α‐glucosidase (HdAgl) was purified from the digestive fluid of Pacific abalone, and its cDNA was cloned [31]. Sequences homologous with the internal sequences of A. kurodai α‐glucosidases were not found in the whole HdAgl sequence.…”

“…The 98-kDa abalone a-glucosidase (98-kDa HdAgl) preferably hydrolyzed smaller substrates such as maltose and maltotriose [31]. Starch was also hydrolyzed to glucose by the abalone enzyme; however, sucrose and isomaltose were not cleaved by abalone a-glucosidase.…”

“…Compared with bacterial and fungal α‐glucosidase reports, there are very few reports concerning enzymatic characterization of α‐glucosidase purified from invertebrates. To date, invertebrate α‐glucosidase has been purified from honeybee ( Apis cerana ) [39], ( A. mellifera ) [25,29], fruit fly ( Drosophila melanogaster ) [40], abalone ( Haliotis discus hannai ) [31], mottled sea hare ( A. fasciata ) [41], and shrimp ( Penaeus vannamei and P. japonicus ) [12,42]. These enzymes belong to GHF 13 but differ in substrate specificity and molecular mass.…”

“…The molecular masses of shrimp and honeybee α‐glucosidase were estimated to be approximately 105 kDa [12] and 68 kDa [29], respectively. The 98‐kDa abalone α‐glucosidase (98‐kDa HdAgl) preferably hydrolyzed smaller substrates such as maltose and maltotriose [31]. Starch was also hydrolyzed to glucose by the abalone enzyme; however, sucrose and isomaltose were not cleaved by abalone α‐glucosidase.…”

Minutaside A, new α‐amylase inhibitor flavonol glucoside from Tagetes minuta: Antidiabetic, antioxidant, and molecular modeling studies

“…Salivary and pancreatic α ‐amylases degrade dietary starch into malto‐oligosaccharides. Then, α ‐glucosidases hydrolyze the glycosidic linkage of malto‐oligosaccharides and produce glucose . Thus, inhibiting these enzymes is a potential way to lower blood glucose.…”