Purification and characterization of alpha-L-fucosidase from the liver of seahare, Aplysia kurodai.

Abstract

An α-L-fucosidase [EC 3.2.1.51] was isolated from liver of the marine gastropod, Aplysia kurodai. The enzyme was purified by procedures involving extraction, ammonium sulfate precipitation, and chromatographies on diethylaminoethyl (DEAE)-Sephadex, hydroxylapatite and Sepharose 6B. The final preparation was sufficiently free from other glycosidase activities and gave a single protein band on disc gel electrophoresis. The molecular weight of the enzyme was estimated to be 330000 by Sephadex G-200 column chromatography. The enzyme has two optimal pH values, one at pH 3.0 and the other at pH 6.4, but it was stable only in the pH range from 4.5 to 6.0. The enzyme released fucose not only from p-nitrophenyl α-L-fucoside but also from human milk oligosaccharides.