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

Substrate-induced structural changes of the pyruvate dehydrogenase multienzyme complex.

B Sümegi, J Batke, Z Porpáczy

    Archives of Biochemistry and Biophysics
    |February 1, 1985
    PubMed
    Summary
    This summary is machine-generated.

    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

    Cardioprotection by resveratrol: A human clinical trial in patients with stable coronary artery disease.

    Clinical hemorheology and microcirculation·2012
    Same author

    Beneficial effect of the insulin sensitizer (HSP inducer) BGP-15 on olanzapine-induced metabolic disorders.

    Brain research bulletin·2010
    Same author

    TIP47 protects mitochondrial membrane integrity and inhibits oxidative-stress-induced cell death.

    FEBS letters·2010
    Same author

    Cloning, sequencing, structural and molecular biological characterization of placental protein 20 (PP20)/human thiamin pyrophosphokinase (hTPK).

    Placenta·2005
    Same author

    Extremely high maternal alkaline phosphatase serum concentration with syncytiotrophoblastic origin.

    Journal of clinical pathology·2004
    Same author

    BGP-15, a hydroximic acid derivative, protects against cisplatin- or taxol-induced peripheral neuropathy in rats.

    Toxicology and applied pharmacology·2003

    The pyruvate dehydrogenase complex shows a lag phase due to its inactive state, which is resolved by substrate binding. This binding induces conformational changes, activating the enzyme complex.

    Area of Science:

    • Biochemistry
    • Enzymology
    • Molecular Biology

    Background:

    • The pyruvate dehydrogenase complex (PDC) catalyzes a key metabolic step, but its reaction kinetics exhibit an unexpected lag phase.
    • Understanding the activation mechanism of PDC is crucial for comprehending cellular energy metabolism.

    Purpose of the Study:

    • To investigate the cause of the lag phase in the pyruvate dehydrogenase complex reaction.
    • To elucidate the role of substrate binding in PDC activation and conformational changes.

    Main Methods:

    • Enzyme kinetics assays to measure reaction lag times.
    • Fluorescence spectroscopy to monitor FAD (flavin adenine dinucleotide) fluorescence quenching and anisotropy.
    • Preincubation experiments with various substrates and cofactors.

    Related Experiment Videos

    Main Results:

    • The lag phase in PDC activity is significantly reduced or eliminated by preincubation with substrates, particularly pyruvate, thiamine pyrophosphate, and CoA.
    • Substrate binding induces conformational changes in PDC, evidenced by altered FAD fluorescence quenching and mobility.
    • The kinetics of FAD fluorescence changes correlate with the observed lag phase, suggesting a link between conformational transitions and enzyme activation.

    Conclusions:

    • The pyruvate dehydrogenase complex exists in a partially inactive conformation in the absence of substrates.
    • Substrate binding triggers a cascade of conformational changes throughout the multienzyme complex, leading to its activation.
    • These findings provide insights into the dynamic regulation of metabolic pathways involving PDC.