The Lipid Peroxidation Product 4-Hydroxynonenal Potently and Selectively Inhibits Synaptic Plasma Membrane Ecto-ATPase Activity, A Putative Regulator of Synaptic ATP and Adenosine

Content Provider	Semantic Scholar
Author	Foley, Timothy D.
Copyright Year	2004
Abstract	Synaptic plasma membrane (SPM)-bound, extracellular-facing (ecto) ATPases are Mg2+- or Ca2+-activated enzymes that regulate the synaptic levels of the excitatory neurotransmitter ATP and provide ADP for the further ecto-nucleotidase-mediated production of the inhibitory neuromodulator adenosine. The present results show that low concentrations (IC50 = 4 μM) of the lipid peroxidation product 4-hydroxynonenal (HNE) inhibited up to about 80% of the ecto-ATPase activity of SPM purified from rat brain cerebral cortex. In contrast, low concentrations of HNE did not inhibit the activity of the “intracellular”-facing Na+, K+, Mg2+-ATPase. In addition, the inhibition of SPM ecto-ATPase activity by HNE was largely irreversible and pH-dependent. Furthermore, structure-activity studies demonstrate that inhibition was dependent on the presence of the reactive functional groups of HNE. These findings suggest that HNE selectively inhibits SPM ecto-ATPase activity by a mechanism that may involve the covalent modification of functionally-critical nucleophilic amino acids. It is proposed that inhibition of SPM ecto-ATPase activity could contribute to the mechanisms by which lipid peroxidation and HNE formation promote excitotoxicity.
Starting Page	1241
Ending Page	1248
Page Count	8
File Format	PDF HTM / HTML
DOI	10.1023/A:1020921006221
PubMed reference number	10492519
Journal	Medline
Volume Number	24
Alternate Webpage(s)	https://page-one.springer.com/pdf/preview/10.1023/A:1020921006221
Alternate Webpage(s)	https://doi.org/10.1023/A%3A1020921006221
Journal	Neurochemical Research
Language	English
Access Restriction	Open
Content Type	Text
Resource Type	Article