Circular dichroism of gangliosides from normal and Tay-Sachs tissues

✍ Scribed by Audrey L. Stone; Edwin H. Kolodny

• Publisher: Elsevier Science
• Year: 1971
• Tongue: English
• Weight: 286 KB
• Volume: 6
• Category: Article
• ISSN: 0009-3084
• DOI: 10.1016/0009-3084(71)90065-x

✦ Synopsis

The circular dichroism (CD) of mammalian gangliosides and their derivatives has been studied in the ultraviolet region from 185 to 300 mlt. Four major CD bands contribute in varying proportions to the resultant curve, two from the amino sugar (GalNAc) chromophore [(-) at ~ 210 m,u and (+) at ~ 187 m~u)] and two from the sialic acid (NANA or NGNA) components [(--) at ~ 220 m/~ and (--) at 196 to 202 m.u]. Comparison of optical parameters derived from the CD curves reveals characteristic differences between GM3 and the more complex ganglioside structures, and between the two disialogangliosides, GDla and GDIb. Ganglioside G~T2, which accumulates in the brain of children with Tay-Sachs disease, has conformations similar to the GM2 prepared from a mixture of normal rat brain gangliosides on the basis of their optical properties. Furthermore, the conformation of the ketosidic bond in CMP-NANA, the intermediate in sialyl transferase reactions, is a as judged by the sign of its 196 m/t sialyl-CD band.