An enzyme with -l-rhamnosidase activity was purified by anion exchange chromatography from an Aspergillus niger commercial preparation. The -l-rhamnosidase was shown to be N-glycosylated, and had a molecular mass of 85 kD on sodium dodecylsulfate-polyacrylamide gel electrophoresis of which approximately 12% was contributed by carbohydrate. The enzyme was optimally active at pH 4.5 and 65°C. When tested towards p-nitrophenyl--l-rhamnopyranoside it showed Km and Vmax values of 2.9 mM and 20.6 U mg−1, respectively whereas it was inhibited competitively by l-rhamnose (Ki 3.5 mM). Substrate specificity studies showed -l-rhamnosidase to be active both on -1,2 and -1,6 linkages to β-d-glucose. Moreover, the enzyme was able to release l-rhamnose from geranyl-β-d-rutinoside and 2-phenylethyl-β-d-rutinoside.
|Journal||FEMS Microbiology Letters|
|Publication status||Published - 1997|
Manzanares, P., de Graaff, L. H., & Visser, J. (1997). Purification and characterization of an -L-rhamnosidase from Aspergillus niger. FEMS Microbiology Letters, 157(2), 279-283. https://doi.org/10.1111/j.1574-6968.1997.tb12785.x