ION CHANNELS IN THE THYLAKOID MEMBRANE (A PATCH-CLAMP STUDY)
Autor(en): | ENZ, C STEINKAMP, T WAGNER, R |
Stichwörter: | Biochemistry & Molecular Biology; Biophysics; CHLOROPLAST; CO2 FIXATION; ELECTRON TRANSPORT; INTACT CHLOROPLASTS; ION CHANNEL; LIGHT-DEPENDENT CHANGES; MEMBRANE POTENTIAL; PHOTOPHOSPHORYLATION; STROMAL MG2+ CONCENTRATION; THYLAKOID MEMBRANE | Erscheinungsdatum: | 1993 | Herausgeber: | ELSEVIER SCIENCE BV | Enthalten in: | BIOCHIMICA ET BIOPHYSICA ACTA | Band: | 1143 | Ausgabe: | 1 | Startseite: | 67 | Seitenende: | 76 | Zusammenfassung: | Thylakoid membranes were fused with azolectin liposomes and enlarged to giant thylakoid/liposome vesicles with diameters between 20 mum and 50 mum by a modified dehydration/rehydration procedure. Ion transport across the membrane of these giant thylakoid/liposome vesicles was investigated by the patch-clamp technique. Single-channel currents were observed and four different specific ion conductances could be distinguished. Our results indicate that these conductances can be attributed to three types of ion channel: a putative potassium channel with a conductance of 110 pS (in 100 mM KCl) a chloride channel with a conductance of 220 pS (in 100 mM KCl) and a moderate selectivity of about 4 : 1 for anions over cations. The third type of putative ion channel we observed was permeable to Mg2+ and Ca2+ ions with conductances of 20 pS for Ca2+ and 35 pS for Mg2+, respectively. |
ISSN: | 00063002 | DOI: | 10.1016/0005-2728(93)90217-4 |
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geprüft am 06.06.2024