Biomaterial Database

The polysialic acid units of the neural cell adhesion molecule N-CAM form filament bundle networks. 1998

J Toikka, and J Aalto, and J Häyrinen, and L J Pelliniemi, and J Finne

Department of Medical Biochemistry, University of Turku, FIN-20520 Turku, Finland.

Polysialic acid is a developmentally regulated component in the neural cell adhesion molecule N-CAM which also occurs as the capsular polysaccharide of bacteria causing meningitis. Polysialic acid has been considered as a repulsive element that regulates intermolecular and intercellular adhesion. Using atomic force microscopy we unexpectedly find that oligomers of polysialic acid assemble with each other into filament bundle networks. Filaments were formed from oligomers containing 12 or more N-acetylneuraminic acid residues, and they were sensitive to sialidase digestion. The networks were also formed by the polysialic acid-containing carbohydrate units of N-CAM. The formation of filament bundles is a novel and unexpected property of polysialic acid and of short carbohydrate oligomers in general and represents a previously unrecognized molecular interaction mechanism which impacts both eukaryotic and prokaryotic cell-cell adhesions.

UI	MeSH Term	Description	Entries
D001704	Biopolymers	Polymers synthesized by living organisms. They play a role in the formation of macromolecular structures and are synthesized via the covalent linkage of biological molecules, especially AMINO ACIDS; NUCLEOTIDES; and CARBOHYDRATES.	Bioplastics,Bioplastic,Biopolymer
D012794	Sialic Acids	A group of naturally occurring N-and O-acyl derivatives of the deoxyamino sugar neuraminic acid. They are ubiquitously distributed in many tissues.	N-Acetylneuraminic Acids,Acids, N-Acetylneuraminic,Acids, Sialic,N Acetylneuraminic Acids
D015816	Cell Adhesion Molecules, Neuronal	Surface ligands that mediate cell-to-cell adhesion and function in the assembly and interconnection of the vertebrate nervous system. These molecules promote cell adhesion via a homophilic mechanism. These are not to be confused with NEURAL CELL ADHESION MOLECULES, now known to be expressed in a variety of tissues and cell types in addition to nervous tissue.	Axon-Associated Adhesion Molecules,Neuronal Cell Adhesion Molecules,Adhesion Molecules, Axon-Associated,Axon Associated Adhesion Molecules,Molecules, Axon-Associated Adhesion
D018625	Microscopy, Atomic Force	A type of scanning probe microscopy in which a probe systematically rides across the surface of a sample being scanned in a raster pattern. The vertical position is recorded as a spring attached to the probe rises and falls in response to peaks and valleys on the surface. These deflections produce a topographic map of the sample.	Atomic Force Microscopy,Force Microscopy,Scanning Force Microscopy,Atomic Force Microscopies,Force Microscopies,Force Microscopies, Scanning,Force Microscopy, Scanning,Microscopies, Atomic Force,Microscopies, Force,Microscopies, Scanning Force,Microscopy, Force,Microscopy, Scanning Force,Scanning Force Microscopies