Endogenous glycosphingolipid acceptor specificity of sialosyltransferase systems in intact golgi membranes, synaptosomes, and synaptic plasma membranes from rat brain

Journal Article · Tue May 17 00:00:00 EDT 1988 · Biochemistry; (United States)

DOI:https://doi.org/10.1021/bi00410a036· OSTI ID:7191242

Durrie, R; Saito, M; Rosenberg, A

Preparations highly enriched in Golgi complex membranes, synaptosomes, and synaptic plasma membranes (SPM) by marker enzyme analysis and electron microscopic morphology were made from the brains of 28-day-old rats. These were incubated with cytidine 5'-monophosphate-N-acetyl(/sup 14/C)neuraminic acid (CMP-NeuAc) in a physiologic buffer, without detergents. Glycolipid sialosyltransferase activities (SATs) were measured by analyzing incorporation of radiolabeled NeuAc into endogenous membrane gangliosides. Golgi SAT was diversified in producing all the various molecular species of labeled gangliosides. Synaptosomal SAT exhibited a lower activity, but it was highly specific in its labeling pattern, with a marked preference for labeling NeuAc..cap alpha..2 ..-->.. 8NeuAc..cap alpha..2 ..-->.. 3Gal..beta..1 ..-->.. 4Glc..beta..1 ..-->.. 1Cer (GD3 ganglioside). SPM prepared from the synaptosomes retained the GD3-related SAT (or SAT-2), and the total specific activity increased, which suggests that the location of the synaptosomal activity is in the SPM. These results indicate that SAT activity in Golgi membranes differs from that in synaptosomes with regard to endogenous acceptor substrate specificity and SAT activity of synaptosomes should be located in the synaptosomal plasma membrane. This SAT could function as an ectoenzyme in concert with ecto-sialidase to modulate the GD3 and other ganglioside population in situ at the SPM of the central nervous system.

• Research Organization: Nathan S. Kline Institute for Psychiatric Research, Orangeburg, NY (USA)
• OSTI ID: 7191242
• Journal Information: Biochemistry; (United States), Vol. 27:10
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
CELL MEMBRANES
MOLECULAR STRUCTURE
TRANSMISSION ELECTRON MICROSCOPY
GANGLIOSIDES
AUTORADIOGRAPHY
BRAIN
CARBON 14 COMPOUNDS
ORGANOIDS
RATS
ANIMALS
BODY
CARBOHYDRATES
CELL CONSTITUENTS
CENTRAL NERVOUS SYSTEM
ELECTRON MICROSCOPY
GLYCOLIPIDS
LABELLED COMPOUNDS
LIPIDS
MAMMALS
MEMBRANES
MICROSCOPY
NERVOUS SYSTEM
ORGANIC COMPOUNDS
ORGANS
RODENTS
SACCHARIDES
VERTEBRATES
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