title: The use of carotenoids and oxonol VI as probes for membrane potential in proteoliposomes.
abstract: Carotenoids present in lipids extracted from the cyanobacterium Synechococcus 6716 indicate trans-membrane potential in proteoliposomes reconstituted from these lipids and the ATPase complex isolated from the same organism. A carotenoid absorbance band shift to a longer wavelength is obtained with valinomycin-induced potassium ion diffusion potentials, irrespective of the polarity of the potassium gradient. In contrast to this, the (externally added) probe oxonol VI only shows an absorbance band shift when the external potassium ion concentration is higher than the internal one. In liposomes without ATPase complex, no carotenoid absorbance band shifts were observed.
authors.forename: H S
authors.initials: HS
authors.lastname: van Walraven
authors.forename: K
authors.initials: K
authors.lastname: Krab
authors.forename: M J
authors.initials: MJ
authors.lastname: Hagendoorn
authors.forename: R
authors.initials: R
authors.lastname: Kraayenhof
mesh_terms: D000251:Adenosine Triphosphatases; D002338:Carotenoids; D000458:Cyanobacteria / Q000378:metabolism; D007555:Isoxazoles; D008564:Membrane Potentials; D010080:Oxazoles; D011188:Potassium / Q000378:metabolism; D011510:Proteolipids
chemical_list: D007555:Isoxazoles; D010080:Oxazoles; D011510:Proteolipids; C020485:proteoliposomes; D002338:Carotenoids; C031184:oxonol VI; D000251:Adenosine Triphosphatases; D011188:Potassium