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ON THE ACTIVATION OF PLASMA MEMBRANE ECTO‐ENZYMES BY TREATMENT WITH NEURAMINIDASE
Author(s) -
Trams E. G.,
Lauter C. J.,
Banfield W. G.
Publication year - 1976
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.1471-4159.1976.tb00305.x
Subject(s) - neuraminidase , enzyme , biochemistry , clostridium perfringens , biology , hamster , microbiology and biotechnology , 5' nucleotidase , chemistry , genetics , bacteria
It had been proposed that sialyl‐residues on the surface of the cell control the activity of certain plasma membrane ecto‐enzymes. We have tested the effects of several established (or presumptive) ecto‐enzymes in tissue cultures of CNS‐derived cells. Application of neuraminidases to cultured mouse neuroblastoma (N‐18), neonatal Syrian hamster astrocytes (NN), human astrocytoma (Cox clone) and two lines of primary mouse astroblasts failed to change the activity of ecto‐ATPase and 5′‐nucleotidase. Only two of the seven neuraminidase preparations produced marked or moderate increases in inorganic pyrophosphatase, p ‐nitrophenylphosphatase and cholinesterase. We have concluded that the stimulation of these enzymes was not due to removal of sialyl‐residues. We suggest that contaminants (haemolysins?) in neuraminidase preparations of Clostridium perfringens increased membrane permeability and facilitated substrate‐product translocation.