title: Alpha-L-rhamnosidase from Aspergillus clavato-nanicus MTCC-9611 active at alkaline pH.
abstract: An alpha-L-rhamnosidase secreting fungal strain has been isolated and identified as Aspergillus clavato-nanicus MTCC-9611. The enzyme was purified to homogeneity from the culture filtrate of the fungus using concentration by ultrafiltration membrane and ion-exchange chromatography on CM-cellulose. The native PAGE analysis confirmed the homogeneity of the purified enzyme. The SDS-PAGE analysis of the purified enzyme revealed a single protein band corresponding to the molecular weight 82 kDa. The alpha-L-rhamnosidase activity of Aspergillus clavato-nanicus MTCC-9611 had optimum at pH 10.0 and 50 degrees C. The K(m) values of the enzyme were 0.65 mM and 0.95 mM using p-nitrophenyl alpha-L-rhamnopyranoside and naringin as a substrates respectively. The enzyme transforms naringin to prunin at pH 10.0 and further hydrolysis of prunin to naringenin does not occur under these reaction conditions that makes alpha-L-rhamnosidase activity of Aspergillus clavatonanicus MTCC-9611 promising enzyme to get prunin for pharmaceutical purposes.
authors: Department of Chemistry, D.D.U. Gorakhpur University, Gorakhpur-276009, India.
authors: Vinita
authors: V
authors: Yadav
authors: Saroj
authors: S
authors: Yadav
authors: Sarita
authors: S
authors: Yadav
authors: K D S
authors: KD
authors: Yadav
mesh_terms: D001230:Aspergillus / Q000201:enzymology*; D044950:Flavanones / Q000737:chemistry*; D005656:Fungal Proteins / Q000737:chemistry* / Q000302:isolation & purification*; D006026:Glycoside Hydrolases / Q000737:chemistry* / Q000302:isolation & purification*; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D013379:Substrate Specificity
chemical_list: D044950:Flavanones; D005656:Fungal Proteins; D006026:Glycoside Hydrolases; C022525:alpha-L-rhamnosidase; C005274:naringin