Biomaterial Database

Biosynthetic incorporation of unnatural sialic acids into polysialic acid on neural cells. 2000

N W Charter, and L K Mahal, and D E Koshland, and C R Bertozzi

Departments of Chemistry and Molecular and Cell Biology, University of California, and Center for Advanced Materials, Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.

In this study we demonstrate that polysialyltransferases are capable of accepting unnatural substrates in terminally differentiated human neurons. Polysialyltransferases catalyze the glycosylation of the neural cell adhesion molecule (NCAM) with polysialic acid (PSA). The unnatural sialic acid analog, N-levulinoyl sialic acid (SiaLev), was incorporated into cell surface glycoconjugates including PSA by the incubation of cultured neurons with the metabolic precursor N-levulinoylmannosamine (ManLev). The ketone group within the levulinoyl side chain of SiaLev was then used as a chemical handle for detection using a biotin probe. The incorporation of SiaLev residues into PSA was demonstrated by protection from sialidases that can cleave natural sialic acids but not those bearing unnatural N-acyl groups. The presence of SiaLev groups on the neuronal cell surface did not impede neurite outgrowth or significantly affect the distribution of PSA on neuronal compartments. Since PSA is important in neural plasticity and development, this mechanism for modulating PSA structure might be useful for functional studies.

UI	MeSH Term	Description	Entries
D009474	Neurons	The basic cellular units of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the NERVOUS SYSTEM.	Nerve Cells,Cell, Nerve,Cells, Nerve,Nerve Cell,Neuron
D011134	Polysaccharides	Long chain polymeric CARBOHYDRATES composed of MONOSACCHARIDES linked by glycosidic bonds.	Glycan,Glycans,Polysaccharide
D002451	Cell Compartmentation	A partitioning within cells due to the selectively permeable membranes which enclose each of the separate parts, e.g., mitochondria, lysosomes, etc.	Cell Compartmentations,Compartmentation, Cell,Compartmentations, Cell
D002454	Cell Differentiation	Progressive restriction of the developmental potential and increasing specialization of function that leads to the formation of specialized cells, tissues, and organs.	Differentiation, Cell,Cell Differentiations,Differentiations, Cell
D002462	Cell Membrane	The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.	Plasma Membrane,Cytoplasmic Membrane,Cell Membranes,Cytoplasmic Membranes,Membrane, Cell,Membrane, Cytoplasmic,Membrane, Plasma,Membranes, Cell,Membranes, Cytoplasmic,Membranes, Plasma,Plasma Membranes
D003569	Cytidine Monophosphate N-Acetylneuraminic Acid	A nucleoside monophosphate sugar which donates N-acetylneuraminic acid to the terminal sugar of a ganglioside or glycoprotein.	CMP Acetylneuraminic Acid,CMP-N-Acetylneuraminic Acid,CMP-NANA,D-glycero-beta-D-galacto-2-Nonulopyranosonic acid, 5-(acetylamino)-3,5-dideoxy-, 2-(hydrogen 5'-cytidylate),CMP-Sialic Acid,Cytidine Monophosphate N Acetylneuraminic Acid,Acetylneuraminic Acid, CMP,CMP N Acetylneuraminic Acid,CMP Sialic Acid
D006001	Glycoconjugates	Carbohydrates covalently linked to a nonsugar moiety (lipids or proteins). The major glycoconjugates are glycoproteins, glycopeptides, peptidoglycans, glycolipids, and lipopolysaccharides. (From Biochemical Nomenclature and Related Documents, 2d ed; From Principles of Biochemistry, 2d ed)	Glycoconjugate
D006595	Hexosamines	AMINO SUGARS created by adding an amine group to a hexose sugar.	Hexosamine
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
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