Related Experiment Videos
Membrane surface potential of Spiroplasma floricola
1Institut für Medizinische Mikrobiologie, Klinikum der Justus Liebig Universität, Giessen, FRG.
FEBS Letters
|August 29, 1988
Summary
Spiroplasma floricola has anionic charges on its outer membrane, creating a negative surface potential. This alters ion distribution, leading to a measured membrane surface potential of -118 mV.
Area of Science:
- Microbiology
- Biophysics
- Cell Biology
Background:
- The outer membrane of Spiroplasma floricola is characterized by anionic charges, identified as lipid phosphate groups.
- These anionic charges establish a negative membrane surface potential, influencing the distribution of ions, particularly protons.
Purpose of the Study:
- To investigate the impact of anionic charges on the membrane surface potential of Spiroplasma floricola.
- To determine the pH at the membrane interface and calculate the membrane surface potential.
Main Methods:
- Cytochemical identification of anionic charges as lipid phosphate groups on the Spiroplasma floricola outer membrane.
- Utilized the fluorescent lipoid pH indicator 4-heptadecyl-7-hydroxycoumarin to measure interfacial pH.
- Calculated membrane surface potential by comparing bulk pH with interfacial pH.
Main Results:
- Anionic charges on the Spiroplasma floricola membrane create a distinct interfacial pH differing from the bulk pH.
- The membrane surface potential of Spiroplasma floricola was calculated to be -118 mV.
Conclusions:
- The negative membrane surface potential is a key characteristic of Spiroplasma floricola's outer membrane.
- This potential significantly influences the local ionic environment at the cell membrane interface.