Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Experiment Videos

Energy dependent hydrogen ion accumulation in submitochondrial particles.

H Rottenberg, C P Lee

    Biochemistry
    |June 17, 1975
    PubMed
    Summary

    The pH gradient across submitochondrial particles is influenced by anion species, with highly lyophilic anions increasing the gradient. This energy-dependent gradient was accurately measured using 9-aminoacridine fluorescence quenching.

    Related Concept Videos

    You might also read

    Related Articles

    Articles linked to this work by shared authors, journal, and citation graph.

    Sort by
    Same author

    Through the lens of history: century-old snapshots from Tsan Yuk Hospital.

    Hong Kong medical journal = Xianggang yi xue za zhi·2025
    Same author

    The use of external pelvimetry in 1948.

    Hong Kong medical journal = Xianggang yi xue za zhi·2024
    Same author

    Travelling back to the 1940s: inspirations from a midwifery casebook written between 1947 and 1948.

    Hong Kong medical journal = Xianggang yi xue za zhi·2024
    Same author

    Understanding your bag-valve-mask resuscitator.

    BJA education·2023
    Same author

    Maternal and obstetric factors of hepatitis B immunisation failure in Hong Kong: a multicentre prospective study: abridged secondary publication.

    Hong Kong medical journal = Xianggang yi xue za zhi·2020
    Same author

    Composite metal substrate for thin film AlGaInP LED applications.

    Optics express·2019

    Area of Science:

    • Mitochondrial physiology
    • Bioenergetics
    • Membrane transport

    Background:

    • Submitochondrial particles (SMPs) are crucial for studying mitochondrial energy transduction.
    • The pH gradient (ΔpH) across the inner mitochondrial membrane is a key component of the proton motive force.
    • Fluorescence quenching of probes like 9-aminoacridine (9AA) is a common method for assessing ΔpH.

    Purpose of the Study:

    • To investigate the influence of anion species on the energy-dependent pH gradient across beef heart SMPs.
    • To compare the reliability of 9-aminoacridine (9AA) and quinacrine (QA) fluorescence quenching for ΔpH measurements.
    • To examine the effects of ionophores and electron transport rates on the ΔpH.

    Main Methods:

    • Utilized fluorescence quenching of 9-aminoacridine (9AA) to measure the pH gradient across beef heart SMPs.
    • Validated 9AA measurements by comparing with ammonium (NH4+) uptake assays.
    • Employed quinacrine (QA) fluorescence quenching as a comparative method.
    • Manipulated electron transport rates using succinate or NADH and rotenone.
    • Applied ionophores like nigericin and valinomycin to modulate the pH gradient.

    Main Results:

    • The pH gradient across SMPs is strongly dependent on the presence and type of anion species in the medium.
    • Highly lyophilic anions (SCN- > I- > NO3- > Br- > Cl-) significantly increase the measured ΔpH.
    • 9AA fluorescence quenching provided valid ΔpH measurements, correlating well with NH4+ uptake.
    • QA fluorescence quenching yielded inconsistent results, differing quantitatively and qualitatively from NH4+ measurements.
    • Carbonyl cyanide p-trifluoromethoxyphenylhydrazone and NH4+ effectively dissipated the ΔpH.
    • Nigericin decreased ΔpH, with valinomycin antagonizing this effect at low concentrations but being overcome at higher concentrations.

    Conclusions:

    • 9-aminoacridine is a reliable probe for measuring the pH gradient across beef heart SMPs.
    • The nature of anions in the external medium significantly impacts the magnitude of the mitochondrial pH gradient.
    • Anion permeability is a critical factor influencing the stability and measurement of the proton motive force in mitochondria.

    Related Experiment Videos