title: Membrane glycoproteins involved in neurite fasciculation.
abstract: Lectin affinity chromatography combined with mAb production was used to identify chick neural cell surface molecules related to L1 antigen, a mouse neural glycoprotein implicated in cell-cell adhesion (Rathjen, F. G., and M. Schachner, 1984, EMBO (Eur. Mol. Biol. Organ.) J., 3:1-10). A glycoprotein, G4 antigen, isolated by mAb G4 from adult chick brain is described which comprises a major 135-kD component, a minor doublet at 190 kD, and diffusely migrating bands at 80 and 65 kD in SDS PAGE. This molecule is structurally related to mouse L1 antigen according to NH2-terminal amino acid sequence (50% identity) as well as the behavior of its components in two-dimensional IEF/SDS PAGE gels. A second chicken glycoprotein, F11 antigen, was isolated from adult chick brain using mAb F11. This protein has also a major 135-kD component and minor components at 170 kD and 120 kD. Both immunotransfer analysis with polyclonal antibodies to mAb G4 and to mAb F11 isolate and the behavior on IEF/SDS PAGE gels indicates that the major 135-kD component of F11 antigen is distinct from G4 antigen components. However, the 135-kD component of F11 antigen shares with G4 antigen and the neural cell adhesion molecule (NCAM) the HNK-1/L2 carbohydrate epitope. In immunofluorescence studies, G4 and F11 antigenic sites were found to be associated mainly with the surface of process-bearing cells, particularly in fiber-rich regions of embryonic brain. Although Fab fragments of polyclonal antibodies to mAbs G4 or F11 immunoaffinity isolate only weakly inhibit the Ca2+-independent aggregation of neural cells, they strongly inhibit fasciculation of retinal axons. Together these studies extend the evidence that bundling of axons reflects the combined effects of a group of distinct cell surface glycoproteins.
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal; D000954:Antigens, Surface / Q000302:isolation & purification / Q000502:physiology*; D001369:Axons / Q000502:physiology*; D001921:Brain / Q000502:physiology*; D002449:Cell Aggregation; D002462:Cell Membrane / Q000502:physiology; D002478:Cells, Cultured; D002642:Chick Embryo; D002645:Chickens; D039841:Leukocyte L1 Antigen Complex; D051379:Mice; D008970:Molecular Weight; D009419:Nerve Tissue Proteins / Q000502:physiology*; D012160:Retina / Q000166:cytology; D013329:Structure-Activity Relationship; D013477:Superior Colliculi / Q000166:cytology
chemical_list: D000911:Antibodies, Monoclonal; D000954:Antigens, Surface; D039841:Leukocyte L1 Antigen Complex; D009419:Nerve Tissue Proteins