Glycoconjugate Journal 1993-12-01

Action of alpha-L-fucoside from Octopus vulgaris hepatopancreas on phospholipid vesicles containing the fucosylated ganglioside FucGM1.

A Giuliani, P Palestini, A D'Aniello, M Masserini

Index: Glycoconj. J. 10(6) , 447-52, (1993)

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Abstract

The behaviour of a highly purified alpha-L-fucosidase (E.C. 3.2.1.51) extracted from octopus hepatopancreas was studied with phospholipid vesicles composed of phosphatidylcholine (PC) and phosphatidylserine (PS) containing the fucosylated ganglioside FucGM1, a potential natural substrate of the enzyme. The substrate recognition and hydrolysis take place only with PS/FucGM1 mixtures via an association process of the enzyme with the vesicles at acidic pH; the enzyme rapidly and stably binds to PS vesicles but not to PC vesicles. The data suggest that only the PS-associated enzyme is able to hydrolyse FucGM1 embedded in the same bilayer. The enzyme association with FucGM1/PS vesicles is a prerequisite for ganglioside hydrolysis but is followed by irreversible enzyme inactivation.