Purification and characterisation of a novel α‐L‐rhamnosidase exhibiting transglycosylating activity from Aspergillus oryzae

Abstract

A novel a-L-rhamnosidase was isolated and purified from Aspergillus oryzae NL-1. The enzyme was purified 13.2-fold by ultrafiltration, ion exchange and gel filtration chromatography with an overall recovery of 6.4% and specific activity of 224.4 U/mg, and the molecular mass of its subunit was approximately 75 kDa. Its optimal temperature and pH were 65°C and 4.5, respectively. The enzyme was stable in the pH range 3.5-7.0, and it showed good thermostability at higher temperatures. The K M , kcat and kcat/K M values were 5.2 mM, 1624 s À1 and 312 s À1 mM À1 using pNPR as substrates, respectively. Moreover, the enzyme exhibited transglycosylating activity, which could synthesise rhamnosyl mannitol through the reactions of transglycosylation with inexpensive rhamnose as the glycosyl donor. Our findings indicate that the enzyme has potential value for glycoside synthesis in the food industry.

Production of Prunin and Naringenin by Using Naringinase from Aspergillus oryzae NYO-2 and Their Neuroprotective Properties and Debitterization

“…oryzae 11,250 and A. oryzae NL-1, each having one subunit with MWs of 23 and 75 kDa, respectively. , Among them, the large subunit was determined as α-L-rhamnosidase and the small subunit was determined as β-glucosidase (data not shown). In addition, the naringinase from Aspergillus aculeatus JMUdb058 has been reported to be composed of four subunits with MWs of 100, 95, 84, and 60 kDa.…”

“…8,15,33 Naringinase from A. oryzae NL-1 hydrolyzed naringin with 21.0% relative activity, and there was no report of β-glucosidase. 35 Naringinase from A. aculeatus JMUdb058 expressed a 95.33% hydrolysis rate when using prunin as the substrate to analyze β-glucosidase but only a 22.68% hydrolysis rate when using naringin to analyze α-Lrhamnosidase; the product of hydrolyzing naringin using this enzyme was not reported. Naringenin was the main formation product of hydrolyzing naringin using commercial naringinase from Penicillium decumbens.…”

“…8,33,34 In this study, the purified naringinase from Aspergillus oryzae NYO-2 contained two subunits with MWs of 92 and 54 kDa on SDS-PAGE analysis (Figure S1), which is different from naringinase from A. oryzae 11,250 and A. oryzae NL-1, each having one subunit with MWs of 23 and 75 kDa, respectively. 8,35 Among them, the large subunit was determined as α-L-rhamnosidase and the small subunit was determined as β-glucosidase (data not shown). In addition, the naringinase from Aspergillus aculeatus JMUdb058 has been reported to be composed of four subunits with MWs of 100, 95, 84, and 60 kDa.…”

“…sojae was prunin. ,, Naringinase from A. oryzae NL-1 hydrolyzed naringin with 21.0% relative activity, and there was no report of β-glucosidase . Naringinase from A.…”

Effects of β-glucosidase and α-rhamnosidase on the Contents of Flavonoids, Ginkgolides, and Aroma Components in Ginkgo Tea Drink

“…The main glyco-ligands in ginkgo flavonoids are composed of glucose or rhamnose, or both [19,20]. β-glucosidase and α-rhamnosidase are two common glycoside hydrolases, which are reported to be able to finish the enzymatic de-glycosylation of many nature flavone glycosides [16,21,22].…”