Which component is responsible for the negative charge of gangliosides?
Acidic character gangliosides derives sialic acid carboxylate not phosphate sulfate fatty acid groups. N acetylneuraminic acid NANA nine carbon sugar pKa about two point six due alpha keto acid carboxyl fully ionized pH seven point four conferring net negative charge and electrophoretic mobility. Monosialoganglioside GM1 carries one charge disialo GD1a two trisialo GT1b three tetra GT1c four enabling separation DEAE anion exchange thin layer chromatography migration anode toward positive electrode. Charge influences calcium bridging modulation binding extracellular matrix proteins complement f
Ref: Schauer R., Glycoconjugate J 2000, Sialic acid chemistry ganglioside negative charge and functions.
