title: Specific binding of GM1-binding peptides to high-density GM1 in lipid membranes.
abstract: The ganglioside Galbeta1-3GalNAcbeta1-4(Neu5Acalpha2-3)Galbeta1-4Glcbeta1-1'Cer (GM1) is an important receptor. We have previously identified GM1-binding peptides based on affinity selection from a random peptide library. In the present study, we determined the amino acids essential for binding GM1 and investigated the specific interaction with GM1 in the lipid membrane. Arginines and aromatic amino acids in the consensus sequence (W/F)RxL(xP/Px)xFxx(Rx/xR)xP contributed to the ability of the peptides to bind GM1. The peptide p3, VWRLLAPPFSNRLLP, having the consensus sequence, showed high affinity for GM1 with a dissociation constant of 1.2 microM. Furthermore, the density-dependent binding of p3 was investigated using mixed monolayers of GM1 and Glcbeta1-1'Cer (GlcCer). p3 binds preferentially to high-density GM1, and its interaction with GM1 was found to be cooperative based on a Hill plot. These results indicated that a lateral assembly of GM1 molecules was required for the recognition of carbohydrates by p3. The GM1-binding peptide played a role as a unique anti-GM1 probe differing from the cholera toxin B subunit or antibodies.
authors.affiliation: Department of Biosciences and Informatics, Keio University, 3-14-1 Hiyoshi, Kouhoku-ku, Yokohama 223-8522, Japan.
authors.forename: Teruhiko
authors.initials: T
authors.lastname: Matsubara
authors.forename: Kazutoshi
authors.initials: K
authors.lastname: Iijima
authors.forename: Miwa
authors.initials: M
authors.lastname: Nakamura
authors.forename: Takao
authors.initials: T
authors.lastname: Taki
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Okahata
authors.forename: Toshinori
authors.initials: T
authors.lastname: Sato
mesh_terms: D000595:Amino Acid Sequence; D001120:Arginine / Q000737:chemistry; D001667:Binding, Competitive; D002772:Cholera Toxin / Q000737:chemistry; D005677:G(M1) Ganglioside / Q000737:chemistry*; D008051:Lipid Bilayers / Q000737:chemistry*; D008055:Lipids / Q000737:chemistry; D018625:Microscopy, Atomic Force; D008956:Models, Chemical; D008958:Models, Molecular; D008968:Molecular Conformation; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry; D011485:Protein Binding; D011791:Quartz
chemical_list: D008051:Lipid Bilayers; D008055:Lipids; D010455:Peptides; D011791:Quartz; D005677:G(M1) Ganglioside; D002772:Cholera Toxin; D001120:Arginine