Characterization of the kinetics of neural cell adhesion molecule homophilic binding.
A solid-phase assay has been developed for the investigation of the kinetics of neural cell adhesion molecule (NCAM) binding. Using this assay we can show that NCAM binds to itself in a time-dependent and saturable manner. Binding constants (KB values) of 6.9 x 10(-8) M and 1.23 x 10(-6) M, respectively, were obtained for adult and newborn rat NCAM homophilic binding. Binding is specifically inhibited by Fab' fragments of polyclonal anti-NCAM antibodies but is unaffected by heparin or chondroitin sulphate. This indicates that the NCAM homophilic binding site is separate from and independent of the heparin-binding site and that a developmental modification, probably polysialation, gives rise to marked differences in the adhesive properties of NCAM.
Moran
N
N
Protein Laboratory, University of Copenhagen, Denmark.
Bock
E
E
D000818:Animals; D000831:Animals, Newborn / Q000378:metabolism*; D000954:Antigens, Surface / Q000276:immunology / Q000378:metabolism*; D015815:Cell Adhesion Molecules; D002809:Chondroitin Sulfates / Q000494:pharmacology; D003101:Collodion; D006493:Heparin / Q000494:pharmacology; D007140:Immunoglobulin Fab Fragments; D007700:Kinetics; D011485:Protein Binding; D051381:Rats
D000954:Antigens, Surface; D015815:Cell Adhesion Molecules; D007140:Immunoglobulin Fab Fragments; D003101:Collodion; D006493:Heparin; D002809:Chondroitin Sulfates