title: Expression and biochemical characterization of recombinant α-l-rhamnosidase r-Rha1 from Aspergillus niger JMU-TS528.
abstract: A putative cDNA of α-l-rhamnosidase was PCR-cloned from Aspergillus niger JMU-TS528 and further extracellular over-expressed in Pichia pastoris GS115. The activity of the recombinant α-l-rhamnosidase r-Rha1 was 711.9U/mL, eightfold higher than the native α-l-rhamnosidase from A. niger JMU-TS528. r-Rha1 is a N-glycosylated protein of 90kDa and possesses broad substrate specificities by hydrolyzing α-1,2, α-1,3 α-1,4, and α-1,6 linkages to β-d-glucosides. This is the first report presenting that α-l-rhamnosidase showed activity on four kinds of glucosidic linkages. Compared with other previously characterized α-l-rhamnosidases, r-Rha1 showed a good thermostability and wide range of pH-stability with the optimum pH of 5.0 and temperature of 60°C. r-Rha1 activity was not greatly affected by representative metal ions and other detected effectors and showed excellent tolerance abilities against glucose and ethanol. These beneficial characteristics of r-Rha1 suggest that r-Rha1 should be considered a potential new biocatalyst for food and drug industrial applications.
authors.affiliation: College of Food and Biological Engineering, Jimei University, Xiamen 361021, China; Fujian Provincial Key Laboratory of Food Microbiology and Enzyme Engineering, Xiamen 361021, China; Research Center of Food Biotechnology of Xiamen City, Xiamen 361021, China.
authors.forename: Lijun
authors.initials: L
authors.lastname: Li
authors.affiliation: College of Food and Biological Engineering, Jimei University, Xiamen 361021, China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Yu
authors.affiliation: College of Food and Biological Engineering, Jimei University, Xiamen 361021, China.
authors.forename: Xia
authors.initials: X
authors.lastname: Zhang
authors.affiliation: College of Food and Biological Engineering, Jimei University, Xiamen 361021, China; Fujian Provincial Key Laboratory of Food Microbiology and Enzyme Engineering, Xiamen 361021, China; Research Center of Food Biotechnology of Xiamen City, Xiamen 361021, China.
authors.forename: Zedong
authors.initials: Z
authors.lastname: Jiang
authors.affiliation: College of Food and Biological Engineering, Jimei University, Xiamen 361021, China; Fujian Provincial Key Laboratory of Food Microbiology and Enzyme Engineering, Xiamen 361021, China; Research Center of Food Biotechnology of Xiamen City, Xiamen 361021, China.
authors.forename: Yanbing
authors.initials: Y
authors.lastname: Zhu
authors.affiliation: College of Food and Biological Engineering, Jimei University, Xiamen 361021, China; Fujian Provincial Key Laboratory of Food Microbiology and Enzyme Engineering, Xiamen 361021, China; Research Center of Food Biotechnology of Xiamen City, Xiamen 361021, China.
authors.forename: Anfeng
authors.initials: A
authors.lastname: Xiao
authors.affiliation: College of Food and Biological Engineering, Jimei University, Xiamen 361021, China; Fujian Provincial Key Laboratory of Food Microbiology and Enzyme Engineering, Xiamen 361021, China; Research Center of Food Biotechnology of Xiamen City, Xiamen 361021, China. Electronic address: nihui@jmu.edu.cn.
authors.forename: Hui
authors.initials: H
authors.lastname: Ni
authors.affiliation: College of Food and Biological Engineering, Jimei University, Xiamen 361021, China; Department of Food, Nutrition and Package Science, Clemson University, South Carolina 29634, United States.
authors.forename: Feng
authors.initials: F
authors.lastname: Chen
mesh_terms: D001234:Aspergillus niger / Q000235:genetics*; D003001:Cloning, Molecular; D004789:Enzyme Activation; D015870:Gene Expression; D006026:Glycoside Hydrolases / Q000037:antagonists & inhibitors / Q000737:chemistry* / Q000235:genetics*; D006863:Hydrogen-Ion Concentration; D008670:Metals / Q000737:chemistry; D011994:Recombinant Proteins; D017422:Sequence Analysis, DNA; D013379:Substrate Specificity; D013696:Temperature
chemical_list: D008670:Metals; D011994:Recombinant Proteins; D006026:Glycoside Hydrolases; C022525:alpha-L-rhamnosidase
keywords: Aspergillus niger; Enzymatic characteristics; Extracellular expression; Pichia pastoris; Recombinant α-l-rhamnosidase