{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2022,10,27]],"date-time":"2022-10-27T13:31:04Z","timestamp":1666877464641},"reference-count":0,"publisher":"Walter de Gruyter GmbH","issue":"1-2","license":[{"start":{"date-parts":[[1982,2,1]],"date-time":"1982-02-01T00:00:00Z","timestamp":381369600000},"content-version":"unspecified","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc-nd\/3.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[1982,2,1]]},"abstract":"<jats:p>When unilamellar vesicles are prepared in the presence of 3-Palmitoyl-7-oxy-coumarin (abbreviation 3P-UBF) this lipoid pH-Indicator is anchored by its fatty acid chain to the membrane and can be used to measure pH-changes at the outer and inner membrane surface (ranging from pH 5 to pH 9.5). By rapidly-changing the pH of the outer aqueous phase a pH- gradient is set up across the vesicle membrane. The rate of the subsequent H<jats:sup>+<\/jats:sup> or OH<jats:sup>-<\/jats:sup> influx into the vesicles can be measured as a change of the 3P-UBF absorbance at 424 nm. This was done with a stopped-flow-spectrophotometer at temperatures between 10 \u00b0C and 50 \u00b0C. <\/jats:p>\n               <jats:p>Suspensions of vesicles prepared from egg-lecithin or \u029f-dipalmitoyl-lecithin were investigated in buffered salt solutions. The influence of Na<jats:sup>+<\/jats:sup>, K<jats:sup>+<\/jats:sup>, Cl<jats:sup>-<\/jats:sup>, SO<jats:sub>4<\/jats:sub>\n                  <jats:sup>2-<\/jats:sup> and valinomycin on the rate of absorbance changes was studied at different temperatures. <\/jats:p>\n               <jats:p>It was found that the rate of the pH-equilibration between the aqueous phase outside and inside the vesicles depends on the direction of the pH-gradient. This new result together with a high H<jats:sup>+<\/jats:sup>\/OH<jats:sup>-<\/jats:sup> permeability of vesicle membranes found in recent studies from other laboratories and confirmed by this investigation is interpreted to indicate a higher permeability of the vesicle membrane to OH<jats:sup>-<\/jats:sup>-ions compared to H<jats:sup>+<\/jats:sup>-ions. (Calculated values are: P<jats:sub>OH<\/jats:sub> = 1.4 \u00d7 10<jats:sup>-4<\/jats:sup>cm\/s at pH 9 and P<jats:sub>H<\/jats:sub> = 8.3 \u00d7 10<jats:sup>-7<\/jats:sup> cm\/s at pH 5 and 20 \u00b0C.) All data described in the literature in detail agree with this suggestion but a pH-dependence of P<jats:sub>OH<\/jats:sub> and P<jats:sub>H<\/jats:sub> cannot be excluded. <\/jats:p>","DOI":"10.1515\/znc-1982-1-221","type":"journal-article","created":{"date-parts":[[2018,8,2]],"date-time":"2018-08-02T17:38:52Z","timestamp":1533231532000},"page":"120-128","source":"Crossref","is-referenced-by-count":8,"title":["Kinetics of Proton-Hydroxyl Transport across Lecithin Vesicle Membranes as Measured with a Lipoid pH-Indicator"],"prefix":"10.1515","volume":"37","author":[{"given":"W. G.","family":"Pohl","sequence":"first","affiliation":[{"name":"Fakult\u00e4t Biologie, Universit\u00e4t Konstanz, Universit\u00e4tsstr. 10, D-7750 Konstanz"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"374","published-online":{"date-parts":[[2014,6,2]]},"container-title":["Zeitschrift f\u00fcr Naturforschung C"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.degruyter.com\/view\/journals\/znc\/37\/1-2\/article-p120.xml","content-type":"text\/html","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/www.degruyter.com\/document\/doi\/10.1515\/znc-1982-1-221\/xml","content-type":"application\/xml","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/www.degruyter.com\/document\/doi\/10.1515\/znc-1982-1-221\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2021,6,22]],"date-time":"2021-06-22T14:02:38Z","timestamp":1624370558000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.degruyter.com\/document\/doi\/10.1515\/znc-1982-1-221\/html"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1982,2,1]]},"references-count":0,"journal-issue":{"issue":"1-2","published-online":{"date-parts":[[2014,6,2]]},"published-print":{"date-parts":[[1982,2,1]]}},"alternative-id":["10.1515\/znc-1982-1-221"],"URL":"https:\/\/doi.org\/10.1515\/znc-1982-1-221","relation":{},"ISSN":["1865-7125","0939-5075"],"issn-type":[{"value":"1865-7125","type":"electronic"},{"value":"0939-5075","type":"print"}],"subject":[],"published":{"date-parts":[[1982,2,1]]}}}