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THE REGIONAL DISTRIBUTION OF SIALOGLYCOPROTEINS, GANGLIOSIDES AND SIALIDASE IN BOVINE BRAIN
Author(s) -
Roukema P. A.,
Heijlman J.
Publication year - 1970
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.1970.tb03348.x
Subject(s) - sialoglycoproteins , sialidase , sialic acid , grey matter , white matter , biochemistry , ganglioside , sialoglycoprotein , chemistry , cerebellum , biology , neuraminidase , enzyme , endocrinology , medicine , magnetic resonance imaging , radiology
— Sialoglycoproteins and gangliosides were characterized in various bovine brain regions by determining the amount of sialic acid. Expressed per g dry weight, the gangliosidic sialic acid ranged from 11·20 to 1·93 μmol and the glycoprotein sialic acid from 8·93 to 1·84 μmol in grey and white matter respectively (values not corrected for incomplete release and breakdown during hydrolysis). Both the sialoglycoproteins and the gangliosides occur in highest concentration in areas predominating in neuronal cell bodies (cerebral grey, cerebellar grey, caudate nucleus). The lowest concentrations are found in those areas, consisting largely of myelinated fibre tracts and glial cells (pons, medulla, corpus callosum, cerebral white). Relative to the gangliosides the sialoglycoproteins are somewhat more concentrated in white matter. The sialidase activity was investigated with endogenous substrate as well as with additional gangliosides or sialoglycopeptides. In all conditions the activity was much greater in grey matter than in white matter. The regional sialidase distribution more or less parallels the distribution of sialic acid in the various regions. At high substrate level the sialoglycopeptides inhibit the sialidase activity. There are indications that gangliosides are a far better substrate for brain sialidase than glycoproteins or glycopeptides. The possible significance of this phenomenon is discussed.