On the activation of plasma membrane ecto-enzymes by treatment with neuraminidase.
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.
Trams
E G
EG
National Institute of Neurological and Communicative Disorders, Stroke and National Cancer Institute, National Institutes of Health, Department of Health, Education and Welfare, Bethesda, MD 20014, USA.
Lauter
C J
CJ
Banfield
W G
WG
D009597:4-Nitrophenylphosphatase / Q000187:drug effects / Q000378:metabolism; D015720:5'-Nucleotidase / Q000187:drug effects / Q000378:metabolism*; D000110:Acetylcholinesterase / Q000187:drug effects / Q000378:metabolism; D000251:Adenosine Triphosphatases / Q000187:drug effects / Q000378:metabolism*; D000818:Animals; D001253:Astrocytes / Q000201:enzymology; D001254:Astrocytoma / Q000201:enzymology / Q000648:ultrastructure; D002460:Cell Line; D002462:Cell Membrane / Q000201:enzymology*; D002463:Cell Membrane Permeability / Q000187:drug effects; D006224:Cricetinae; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation / Q000187:drug effects; D006801:Humans; D043564:Inorganic Pyrophosphatase; D051379:Mice; D009439:Neuraminidase / Q000494:pharmacology*; D009447:Neuroblastoma / Q000201:enzymology; D011755:Pyrophosphatases / Q000187:drug effects / Q000378:metabolism; D051381:Rats
D000110:Acetylcholinesterase; D009597:4-Nitrophenylphosphatase; D015720:5'-Nucleotidase; D009439:Neuraminidase; D000251:Adenosine Triphosphatases; D011755:Pyrophosphatases; C027201:ectoATPase; D043564:Inorganic Pyrophosphatase