Action of alpha-L-fucoside from Octopus vulgaris hepatopancreas on phospholipid vesicles containing the fucosylated ganglioside FucGM1.
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.
Giuliani
A
A
Department of Biological Chemistry, Medical School, University of Milan, Italy.
Palestini
P
P
D'Aniello
A
A
Masserini
M
M
D000818:Animals; D004064:Digestive System / Q000737:chemistry*; D005677:G(M1) Ganglioside / Q000031:analogs & derivatives* / Q000032:analysis; D006027:Glycosides / Q000737:chemistry; D008051:Lipid Bilayers; D049831:Octopodiformes / Q000737:chemistry*; D010743:Phospholipids / Q000032:analysis*; D013050:Spectrometry, Fluorescence; D013379:Substrate Specificity; D005644:alpha-L-Fucosidase / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*
D006027:Glycosides; D008051:Lipid Bilayers; D010743:Phospholipids; D005677:G(M1) Ganglioside; C046737:4-methylumbelliferyl fucoside; C039123:fucosyl GM1 ganglioside; D005644:alpha-L-Fucosidase