The University of Southampton
University of Southampton Institutional Repository

Multiple binding sites for fatty acids on the potassium channel KcsA

Multiple binding sites for fatty acids on the potassium channel KcsA
Multiple binding sites for fatty acids on the potassium channel KcsA
Interactions of fatty acids with the potassium channel KcsA were studied using Trp fluorescence quenching and electron paramagnetic resonance (EPR) techniques. The brominated analogue of oleic acid was shown to bind to annular sites on KcsA and to the nonannular sites at each protein-protein interface in the homotetrameric structure with binding constants relative to dioleoylphosphatidylcholine of 0.67 ± 0.04 and 0.87 ± 0.08, respectively. Mutation of the two Arg residues close to the nonannular binding sites had no effect on fatty acid binding. EPR studies with a spin-labeled analogue of stearic acid detected a high-affinity binding site for the fatty acid with strong immobilization. Fluorescence quenching studies with the spin-labeled analogue showed that the binding site detected in the EPR experiments could not be one of the annular or nonannular binding sites. Instead, it is proposed that the EPR studies detect binding to the central hydrophobic cavity of the channel, with a binding constant in the range of ~0.1-1 ?M.
2889-2898
Bolivar, Juan H.
e3b126b7-e597-4dad-ac73-bda0c0cab016
Smithers, Natalie
63ead01b-6515-4f82-a963-884f572af872
East, J. Malcolm
9fe7f794-1d89-4935-9a99-b831d786056e
Marsh, Derek
e2ab9365-4e03-43f2-8abe-cb03f222e7ae
Lee, Anthony G.
0891914c-e0e2-4ee1-b43e-1b70eb072d8e
Bolivar, Juan H.
e3b126b7-e597-4dad-ac73-bda0c0cab016
Smithers, Natalie
63ead01b-6515-4f82-a963-884f572af872
East, J. Malcolm
9fe7f794-1d89-4935-9a99-b831d786056e
Marsh, Derek
e2ab9365-4e03-43f2-8abe-cb03f222e7ae
Lee, Anthony G.
0891914c-e0e2-4ee1-b43e-1b70eb072d8e

Bolivar, Juan H., Smithers, Natalie, East, J. Malcolm, Marsh, Derek and Lee, Anthony G. (2012) Multiple binding sites for fatty acids on the potassium channel KcsA. Biochemistry, 51 (13), 2889-2898. (doi:10.1021/bi300153v). (PMID:22409348)

Record type: Article

Abstract

Interactions of fatty acids with the potassium channel KcsA were studied using Trp fluorescence quenching and electron paramagnetic resonance (EPR) techniques. The brominated analogue of oleic acid was shown to bind to annular sites on KcsA and to the nonannular sites at each protein-protein interface in the homotetrameric structure with binding constants relative to dioleoylphosphatidylcholine of 0.67 ± 0.04 and 0.87 ± 0.08, respectively. Mutation of the two Arg residues close to the nonannular binding sites had no effect on fatty acid binding. EPR studies with a spin-labeled analogue of stearic acid detected a high-affinity binding site for the fatty acid with strong immobilization. Fluorescence quenching studies with the spin-labeled analogue showed that the binding site detected in the EPR experiments could not be one of the annular or nonannular binding sites. Instead, it is proposed that the EPR studies detect binding to the central hydrophobic cavity of the channel, with a binding constant in the range of ~0.1-1 ?M.

PDF
bi300153v_East.pdf - Version of Record
Restricted to Repository staff only
Request a copy

More information

e-pub ahead of print date: 12 March 2012
Published date: 3 April 2012
Organisations: Centre for Biological Sciences

Identifiers

Local EPrints ID: 342267
URI: https://eprints.soton.ac.uk/id/eprint/342267
PURE UUID: d768cd94-909a-48ce-92b5-b097718f0cb3

Catalogue record

Date deposited: 20 Aug 2012 14:16
Last modified: 18 Jul 2017 05:30

Export record

Altmetrics

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of https://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×