Membrane phospholipids represent a potential influence on the enzymatic properties of the Na,K-ATPase. Little is known concerning the effects of the fatty acid environment surrounding the enzyme on the kinetic properties of the Na,K-ATPase. We used the most obvious difference among the α isoforms of rat, their affinities for digitalis glycosides, to examine the relationship between the lipid environment and the Na,K-ATPase. Specific membrane environments that differ in their fatty acid composition were produced by drug-induced diabetes, as well as variations in diet. The α1 isoforms in various tissues were then characterized by their resistance to ouabain in Na,K-ATPase-enriched membrane microsomal fractions. The Na,K-ATPase activity in nerves and hearts were altered by diabetes and partially restored in nerves after a fish oil diet. Evaluation of enzyme kinetics (dose-response curves for ouabain) in membrane preparations allowed us to correlate the ouabain affinity of α1 isoform with fatty acid composition. The affinity of the α1 isoform for ouabain was significantly increased with accretions in the total amount of fatty acids of the n-6 series (P < 0.0001). Our observations provide a partial explanation for the observed difference in isoform properties among tissues. Moreover, these results underline the interaction between membrane fatty acids and the glycoside binding site of the Na,K-ATPase α1 subunit.
The Journal of Membrane Biology – Springer Journals
Published: Mar 1, 1999
It’s your single place to instantly
discover and read the research
that matters to you.
Enjoy affordable access to
over 18 million articles from more than
15,000 peer-reviewed journals.
All for just $49/month
Query the DeepDyve database, plus search all of PubMed and Google Scholar seamlessly
Save any article or search result from DeepDyve, PubMed, and Google Scholar... all in one place.
All the latest content is available, no embargo periods.
“Whoa! It’s like Spotify but for academic articles.”@Phil_Robichaud