L-FUCOSE RESIDUES ON CELLULOSE-BASED DIALYSIS MEMBRANES - QUANTIFICATION OF MEMBRANE-ASSOCIATED L-FUCOSE AND ANALYSIS OF SPECIFIC LECTIN-BINDING

Contact of mononuclear human leukocytes with cellulose dialysis membra nes may result in complement-independent cell activation, i.e. enhance d synthesis of cytokines, prostaglandins and an increase in beta 2-mic roglobulin synthesis. Cellular contact activation is specifically inhi bited by the monosaccharide L-fucose suggesting that dialysis membrane associated L-fucose residues are involved in leukocyte activation. In this study we have detected and quantitated L-fucose on commercially- available cellulose dialysis membranes using two approaches. A sensiti ve enzymatic fluorescence assay detected L-fucose after acid hydrolysi s of flat sheet membranes. Values ranged from 79.3 +/- 3.6 to 90.2 +/- 5.0 pmol cm(-2) for Hemophan(R) or Cuprophan(R) respectively. Enzymat ic cleavage of terminal alpha-L-fucopyranoses with alpha-L-fucosidase yielded 7.7 +/- 3.3 pmol L-fucose per cm(2) for Cuprophan. Enzymatic h ydrolysis of the synthetic polymer membranes AN-69 and PC-PE did not y ield detectable amounts of L-fucose. In a second approach, binding of the fucose specific lectins of Lotus tetragonolobus and Ulex europaeus (UEAI) demonstrated the presence of biologically accessible L-fucose on the surface of cellulose membranes. Specific binding was observed w ith Cuprophan(R), and up to 2.6 +/- 0.3 pmol L-fucose per cm(2) was ca lculated to be present from Langmuir-type adsorption isotherms. The da ta presented are in line with the hypothesis that surface-associated L -fucose residues on cellulose dialysis membranes participate in leukoc yte contact activation.