Energy Transfer and Fluorescence Quenching in Chlorophyll Containing Vesicles
Abstract Fluorescence spectroscopic experiments are reported on dimyristoyllecithin (DML) vesicles containing pheophytin a, chlorophyll a or chlorophyll b. From the temperature as well as from the concentration dependence of the fluorescence intensity a phase separation at low temperatures is observ...
Published in: | Berichte der Bunsengesellschaft für physikalische Chemie |
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Main Authors: | , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Wiley
1978
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Subjects: | |
Online Access: | http://dx.doi.org/10.1002/bbpc.19780820930 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fbbpc.19780820930 https://onlinelibrary.wiley.com/doi/pdf/10.1002/bbpc.19780820930 |
Summary: | Abstract Fluorescence spectroscopic experiments are reported on dimyristoyllecithin (DML) vesicles containing pheophytin a, chlorophyll a or chlorophyll b. From the temperature as well as from the concentration dependence of the fluorescence intensity a phase separation at low temperatures is observed: The chlorophylls are solubilized by the DML phase only up to concentrations of the order of 1 mole‐%. the excess molecules being precipitated in domains containing almost exclusively the chlorophylls. – Whereas at high temperatures (30°C) for chlorophyll a containing vesicles a phase separation could not be established, this was possible in the pheophytin case. The pheophytin solubility in the liquid DML phase amounts to about 10 mole‐%, which is consistent with monolayer studies of the system. – The efficiency of energy transfer from chlorophyll b to chlorophyll a increases with decreasing temperature for small chlorophyll concentrations (< 1 mol‐%). This is due to the decrease in intermolecular distance on solidification of the lipid. The temperature dependence of the transfer efficiency is reversed at high chlorophyll concentrations (≤ 20 mole‐%). This is interpreted as a consequence of the decrease of the chlorophyll solubility in the DML phase that causes a decrease in the chlorophyll‐chlorophyll distance. |
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