Ion distribution profiles between polar and charged membranes as observed by anomalous X-ray diffraction

Autor:	H. Richardsen, G. Cevc, U. Vierl, W. Fenzl
Rok vydání:	1996
Předmět:	Diffraction Aqueous solution Materials science Analytical chemistry General Physics and Astronomy chemistry.chemical_element Ion Rubidium Membrane chemistry X-ray crystallography Polar Ion distribution Atomic physics
Zdroj:	Europhysics Letters (EPL). 34:543-548
ISSN:	1286-4854 0295-5075
DOI:	10.1209/epl/i1996-00492-x
Popis:	The distribution profiles of rubidium ions near polar, zwitterionic 1,2-di stearoyl-sn-glycero-3-phospho choline (DSPC) and charged, anionic 1,2-di stearoyl-sn-glycero-3-phospho glycerol (DSPG−) membranes were determined by means of anomalous X-ray diffraction close to the K-absorption edge of Rb+, which was measured to be 15.225 keV. The samples were kept in the Lβ'-phase at 30 °C. The DSPC suspensions in 2 M RbCl were examined at 15.125 keV, 15.196 keV, 15.210 keV, the DSPG− suspensions in 0 M RbCl and 2 M RbCl at 14.667 keV and 15.196 keV. This gave up to seven peaks in the powder-like diffraction pattern and revealed, for the first time directly, different rubidium ion distributions in either of the investigated systems: rubodium ions are enriched by 100% in the proximity of the charged DSPG− headgroups and depleted by 25% from the vicinity of the zwitterionic DSPC headgroups. The latter phenomenon results in rubidium ion concentration maximum in the aqueous compartment between polar, but uncharged bilayers.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::1356d29a880e6c7c1452fb329dbe803c https://doi.org/10.1209/epl/i1996-00492-x Zobrazit plný text záznamu