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

Phosphorylase phosphatase. Interconversion of active and inactive forms.

E Villa-Moruzzi, L M Ballou, E H Fischer

    The Journal of Biological Chemistry
    |May 10, 1984
    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

    Thrombophlebitis migrans.

    The Journal of the Kansas Medical Society·2010
    Same author

    Pancreatic lithiasis.

    The Journal of the Kansas Medical Society·2010
    Same author

    Climate change and the integrity of science.

    Science (New York, N.Y.)·2010
    Same author

    Crystallization of pancreas alpha-amylase.

    Experientia·2010
    Same author

    Physical and chemical properties of crystalline alpha-amylase of hog pancreas.

    Archives of biochemistry·2010
    Same author

    Isolation of alpha-amylase from pancreas.

    Experientia·2010

    Phosphorylase phosphatase, a complex of catalytic and inhibitor 2 subunits, requires specific interactions for activation and inactivation. Protein kinase FA and metal ions like Mn2+ are crucial for regulating this enzyme

    Area of Science:

    • Enzymology
    • Protein biochemistry
    • Signal transduction

    Background:

    • Phosphorylase phosphatase is a key enzyme regulating glycogen metabolism.
    • It exists as an inactive complex of catalytic and regulatory (inhibitor 2) subunits.
    • Understanding its regulation is vital for metabolic research.

    Purpose of the Study:

    • To investigate the roles of the catalytic and inhibitor 2 subunits in phosphorylase phosphatase activity.
    • To elucidate the mechanisms of enzyme activation and inactivation by metal ions and protein kinase FA.
    • To explore the structural changes involved in the activation-inactivation cycle.

    Main Methods:

    • Isolation and separation of phosphorylase phosphatase subunits.
    • Enzyme activity assays with various metal ions (Mn2+, Co2+, Mg2+, Ca2+).

    Related Experiment Videos

  • Phosphorylation studies using protein kinase FA.
  • Reconstitution of enzyme complexes with isolated subunits.

    • Main Results:

    • The isolated catalytic subunit is inactive and requires Mn2+ or Co2+ for activation, but not Mg2+ or Ca2+.
    • Protein kinase FA activates the complex by phosphorylating inhibitor 2, leading to catalytic subunit activation.
    • The regulatory subunit (inhibitor 2) is essential for both activation and inactivation, mediating autodephosphorylation and conformational changes.
    • Reconstituted complexes show that specific subunit interaction is necessary for the activation-inactivation cycle.

    Conclusions:

    • The interaction between the catalytic subunit and inhibitor 2 is critical for the regulation of phosphorylase phosphatase.
    • Metal ions and protein kinase FA induce specific conformational changes essential for enzyme activity.
    • The regulatory subunit plays a pivotal role in mediating the dynamic activation-inactivation process of phosphorylase phosphatase.