Abstract
α-L-Rhamnosidase T from the liver of Turbo cornutus, a marine gastropod, was purified 111-fold using p-nitrophenyl α-L-rhamnoside as a substrate. Column chromatography with CM-cellulose and Sephadex G-150, heat treatment, and freezingand-thawing in acidic pH were useful for the purification.
α-L-Rhamnosidase N of Aspergillus niger was further purified from commercial “Naringinase.”
These two enzymes showed somewhat different properties and specificities.α-L-Rhamnosidase T: pH optimum 2.8, hydrolyzed readily quercitrin, but not naringin.α-L-Rhamnosidase N: pH optimum 4.5-5.0, hydrolyzed readily naringin and rutin, but not quercitrin.
Methyl α-L-rhamnoside and a rhamnosyl 2-keto-3-deoxyoctonate from E. coli K-12 could not be hydrolyzed by the enzymes.
Effects of various substances on the enzymes were studied. No specific inhibitors were found.
Unlike the crude preparation of glycosidases mixture from the liver of Turbo cornutus, the purified α-L-rhamnosidase T did not release rhamnose from the lipopolysaccharide of Pseudomonas aeruginosa.
