title: Synergistic inhibitory activity of alpha- and beta-LFA-1 peptides on LFA-1/ICAM-1 interaction.
abstract: Interactions of cell-adhesion molecule LFA-1 and its ligand ICAM-1 play important roles during immune and inflammatory responses. Critical residues of LFA-1 for ICAM-1 binding are known to be in the I-domain of the alpha-subunit and the I-like domain of the beta-subunit. On the basis of our previous work demonstrating the inhibitory activity of I-domain cyclic peptide cLAB.L on LFA-1/ICAM-1 interaction, here we have explored the activity of I-like-domain peptide LBE on the binding mechanism of cLAB.L. LBE enhances cLAB.L binding to T-cells and epithelial cells. The adherence of T-cells to epithelial monolayers was suppressed by the two peptides. The addition of LBE to the monolayers prior to the addition cLAB.L produced a better inhibitory effect than the reverse procedure. LBE, but not cLAB.L, changes the ICAM-1 conformation, suggesting that LBE binds to ICAM-1 at sites that are distinct from these of cLAB.L and induces improved conformation in ICAM-1 for binding to cLAB.L.
authors.affiliation: Department of Pharmaceutical Chemistry, University of Kansas, Lawrence, KS 66047, USA.
authors.forename: H
authors.initials: H
authors.lastname: Yusuf-Makagiansar
authors.forename: I T
authors.initials: IT
authors.lastname: Makagiansar
authors.forename: Y
authors.initials: Y
authors.lastname: Hu
authors.forename: T J
authors.initials: TJ
authors.lastname: Siahaan
mesh_terms: D018938:Caco-2 Cells; D002460:Cell Line; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000737:chemistry / Q000378:metabolism*; D016169:Lymphocyte Function-Associated Antigen-1 / Q000737:chemistry / Q000378:metabolism*; D008214:Lymphocytes / Q000166:cytology; D010446:Peptide Fragments / Q000378:metabolism*; D011485:Protein Binding; D011487:Protein Conformation; D013050:Spectrometry, Fluorescence
chemical_list: D016169:Lymphocyte Function-Associated Antigen-1; D010446:Peptide Fragments; D018799:Intercellular Adhesion Molecule-1