title: Structure and interactions of NCAM modules 1 and 2, basic elements in neural cell adhesion.
abstract: The structure in solution of the second Ig-module fragment of residues 117-208 of NCAM has been determined. Like the first Ig-module of residues 20-116, it belongs to the I set of the immunogloblin superfamily. Module 1 and module 2 interact weakly, and the binding sites of this interaction have been identified. The two-module fragment NCAM(20-208) is a stable dimer. Removal of the charged residues in these sites in NCAM(20-208) abolishes the dimerization. Modeling the dimer of NCAM(20-208) to fit the interactions of these charges produces one coherent binding site for the formation of two antiparallel strands of the first two NCAM modules. This mode of binding could be a major element in trans-cellular interactions in neural cell adhesion.
authors.affiliation: Department of Chemistry, Carlsberg Laboratory, Valby, Denmark.
authors.forename: P H
authors.initials: PH
authors.lastname: Jensen
authors.forename: V
authors.initials: V
authors.lastname: Soroka
authors.forename: N K
authors.initials: NK
authors.lastname: Thomsen
authors.forename: I
authors.initials: I
authors.lastname: Ralets
authors.forename: V
authors.initials: V
authors.lastname: Berezin
authors.forename: E
authors.initials: E
authors.lastname: Bock
authors.forename: F M
authors.initials: FM
authors.lastname: Poulsen
mesh_terms: D019943:Amino Acid Substitution; D001665:Binding Sites; D002448:Cell Adhesion; D003460:Crystallization; D018360:Crystallography, X-Ray; D019281:Dimerization; D004220:Disulfides / Q000737:chemistry; D007136:Immunoglobulins / Q000737:chemistry; D008958:Models, Molecular; D008969:Molecular Sequence Data; D019006:Neural Cell Adhesion Molecules / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D009474:Neurons / Q000737:chemistry / Q000166:cytology / Q000502:physiology*; D019906:Nuclear Magnetic Resonance, Biomolecular; D010446:Peptide Fragments / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D055672:Static Electricity; D013816:Thermodynamics
chemical_list: D004220:Disulfides; D007136:Immunoglobulins; D019006:Neural Cell Adhesion Molecules; D010446:Peptide Fragments