Binding of biotinylated heparin to MBP-Fim2 fusion proteins. Biotinylated heparin was incubated with immobilized MBP-Fim2 or mutant MBP-Fim2 derivatives harboring deletions (A) or substitutions (B). After being washed, adherent heparin was detected with a streptavidin-peroxidase conjugate. The assay was carried out at least four times, and a representative result is shown. (A) ○, MBP-Fim2; •, MBP-Fim2ΔH2; +, MBP-Fim2ΔH1; ▪, MBP. (B) ▪, MBP-Fim2[179]; □, MBP-Fim2[186-187]; ▴, MBP-Fim2[186]; ○, MBP-Fim2; ▪, MBP.