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

Hydrophobic regions function in calmodulin-enzyme(s) interactions.

T Tanaka, H Hidaka

    The Journal of Biological Chemistry
    |December 10, 1980
    PubMed
    Summary

    Certain lipids and SDS activate calmodulin-dependent enzymes without Ca2+. Calcium binding to calmodulin exposes hydrophobic regions, crucial for enzyme activation, as shown by TNS fluorescence studies.

    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

    Anti-immunoglobulin M activates nuclear calcium/calmodulin-dependent protein kinase II in human B lymphocytes.

    The Journal of experimental medicine·1995
    Same author

    Elucidation of the protein kinase C-dependent apoptosis pathway in distinct subsets of T lymphocytes in MRL-lpr/lpr mice.

    European journal of immunology·1995
    Same author

    Purification and characterization of a novel protein activator of Ca2+/calmodulin-dependent protein kinase I.

    Biochemical and biophysical research communications·1995
    Same author

    Effect of KN-62, Ca2+/calmodulin-dependent protein kinase II inhibitor, on adriamycin resistance of human ovarian cancer cells.

    Biochemical and biophysical research communications·1995
    Same author

    The regulatory region of calcium/calmodulin-dependent protein kinase I contains closely associated autoinhibitory and calmodulin-binding domains.

    The Journal of biological chemistry·1995
    Same author

    Prophylaxis of genetically determined diabetes by diazoxide: a study in a rat model of naturally occurring obese diabetes.

    The Journal of pharmacology and experimental therapeutics·1995

    Area of Science:

    • Biochemistry
    • Molecular Biology
    • Enzymology

    Background:

    • Calmodulin (CaM) is a key calcium-binding protein regulating numerous enzymes.
    • CaM-dependent enzymes play vital roles in cellular signaling pathways.
    • Understanding CaM activation mechanisms is crucial for deciphering cellular processes.

    Purpose of the Study:

    • To investigate the role of hydrophobic interactions in CaM-dependent enzyme activation.
    • To elucidate the conformational changes in CaM upon calcium binding.
    • To identify the molecular basis for CaM's interaction with its target enzymes.

    Main Methods:

    • Enzyme activity assays using bovine brain phosphodiesterase and chicken gizzard myosin light chain kinase.
    • Inhibition studies with 2-p-toluidinyl-naphthalene-6-sulfonate (TNS), a hydrophobic probe.
    • Fluorescence spectroscopy to detect TNS-CaM interactions.
    • Kinetic analysis of enzyme inhibition.

    Main Results:

    • Lipids and SDS activated CaM-dependent enzymes independent of Ca2+.
    • TNS inhibited CaM-dependent enzymes by competing with CaM.
    • TNS fluorescence increased upon Ca2+ binding to CaM, indicating exposure of hydrophobic regions.
    • A CaM-interacting agent suppressed TNS fluorescence, confirming TNS binding to Ca2+-induced hydrophobic sites.

    Conclusions:

    • Ca2+ binding induces a conformational change in CaM, exposing hydrophobic surfaces.
    • These exposed hydrophobic regions are critical for CaM's interaction with and activation of target enzymes.
    • Hydrophobic properties of Ca2+-CaM are essential for Ca2+-CaM-dependent enzyme activity.

    Related Experiment Videos