FIGURE 1.

Competition of CyPB binding to heparin-derived oligosaccharides and cell surface HS. A, ANTS-labeled dp12 (0.6 nmol) and CyPB (0.1 nmol) were mixed in the absence (control) or presence of heparin derivatives or soluble HS (20 μg). After a 30-min incubation, samples were subjected to electrophoretic mobility shift assay. Lane 1, control; lane 2, fully N-desulfated heparin; lane 3, partially N-desulfated heparin; lane 4, porcine mucosal HS; lane 5, bovine kidney HS; lane 6, unmodified heparin. At the end of the electrophoresis, the profile of migration of ANTS-labeled dp12 was imaged after exposure to UV transilluminator for 0.60 s. Representative gel of three separate experiments is shown. B, inhibition of the interaction of CyPB with cell surface HS was analyzed by measuring the binding of Jurkat T cells to immobilized CyPB (1 μg/well) in the absence (control) or presence of increasing concentrations of heparin derivatives or soluble HS as follows: unmodified heparin (●), partially N-desulfated heparin (■), fully N-desulfated heparin (▴), bovine kidney HS (○), and porcine mucosal HS (□). Cell binding was related to the number of initially added cells (0.8 × 10⁶ per well) remaining fixed to the adhesive substrate. Maximal binding in the absence of competitor was 0.52 ± 0.06 × 10⁶ cells per well. Results are expressed as percentages of this maximal value. Points are means ± S.D. of triplicates from at least three separate experiments.