Synthesis and aggregative properties of GM1 ganglioside (IV3Neu5AcGgOse4Cer) containing d-(+)-2-hydroxystearic acid

✍ Scribed by Sandro Sonnino; Domenico Acquotti; Laura Cantu'; Vanna Chigorno; Manuela Valsecchi; Riccardo Casellato; Massimo Masserini; Mario Corti; Piero Allevi; Guido Tettamanti

• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 746 KB
• Volume: 69
• Category: Article
• ISSN: 0009-3084
• DOI: 10.1016/0009-3084(94)90031-0

✦ Synopsis

GM1 ganglioside containing a hydroxylated fatty acid moiety, GMI(OH), was synthesized starting from lyso-GMl and D-(+)-2-hydroxystearic acid. The aggregative, geometrical and distribution properties of GMI(OH) were compared with those of stearic acid containing GM 1 ganglioside; laser light scattering measurements, differential scanning calorimetry and fluorescence spectroscopy were used. GMI and GMI(OH) are present in solution as micelles with a hydrodynamic radius of 58.7 and 60.0 A, and molecular mass of 470 and 570 kDa, respectively. The surface area occupied by the monomer of GMI(OH) at the lipid-water interface of the aggregate was calculated to be 117 .~, 2 which is 3 ,~, : lower than that determined for GM 1. Proton NMR analyses of GMI and GMI(OH) suggest different three-dimensional structures at the ganglioside lipid-water interface. Both GMI(OH) and GMI inserted into dipalmitoylphosphatidylchotine (DPPC) vesicles undergo segregation phenomena, with the formation of gangliosideenriched microdomains, but GMI(OH) shows a higher degree of dispersion in the DPPC matrix and exerts a lower rigidifying effect than does GM1.