title: Weak interaction between inhibition peptides and a soluble receptor of fusion protein in the liquid phase.
abstract: Fluorescence polarization analysis (FPA) of a liquid-phase method was carried out with a glycosylphosphatidylinositol (GPI) anchored membrane receptor bone marrow stromal cell antigen 1 (BST-1, CD157) as a model receptor for medical screening. A soluble receptor, BST1-Fc, was prepared by fusing the extracellular domain of BST-1 and the Fc region of human immunoglobulin G (IgG). The binding curves of BST1-Fc with a fluorescently labeled ligand peptide, or its three derivatives, were developed using ordinary FPA in the liquid phase. The obtained dissociation constants (Kd) were comparable with those reported as measured with SPR of a solid-phase method, except for one derivative peptide with Kd larger than 7000 nM. Competitive FPA was carried out, and it was demonstrated that a very weak interaction, which would be difficult to detect with SPR or other solid-phase methods, could be analyzed with both ordinary and competitive FPA.
authors.affiliation: School of Bionics, Tokyo University of Technology, 1404-1 Katakura, Hachioji, Tokyo 192-0982, Japan.
authors.forename: Masafumi
authors.initials: M
authors.lastname: Shimizu
authors.forename: Yukuya
authors.initials: Y
authors.lastname: Yoshiaki
authors.forename: Atsushi
authors.initials: A
authors.lastname: Sato
authors.forename: Makoto
authors.initials: M
authors.lastname: Tsuruoka
mesh_terms: D036541:ADP-ribosyl Cyclase / Q000096:biosynthesis*; D015703:Antigens, CD / Q000096:biosynthesis*; D002352:Carrier Proteins / Q000737:chemistry; D002623:Chemistry Techniques, Analytical / Q000379:methods*; D004247:DNA / Q000737:chemistry; D004305:Dose-Response Relationship, Drug; D005454:Fluorescence Polarization / Q000379:methods*; D058851:GPI-Linked Proteins; D006801:Humans; D007074:Immunoglobulin G / Q000737:chemistry; D007700:Kinetics; D008024:Ligands; D010455:Peptides / Q000737:chemistry*; D011485:Protein Binding; D011506:Proteins / Q000032:analysis
chemical_list: D015703:Antigens, CD; D002352:Carrier Proteins; D058851:GPI-Linked Proteins; D007074:Immunoglobulin G; D008024:Ligands; D010455:Peptides; D011506:Proteins; D004247:DNA; D036541:ADP-ribosyl Cyclase; C087521:ADP-ribosyl cyclase 2