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

Amyloid A: amphipathic helixes and lipid binding

J P Segrest, H J Pownall, R L Jackson

    Biochemistry
    |July 27, 1976
    PubMed
    Summary

    Amyloid A protein spontaneously binds to lipids, forming complexes. This suggests the amphipathic helix is a key lipid-binding structure in proteins, impacting amyloid A

    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

    Synthesis of saturated, unsaturated, spin-labeled, and fluorescent cholesteryl esters: Acylation of cholesterol using fatty acid anhydride and 4-pyrrolidinopyridine.

    Lipids·2016
    Same author

    Speciated High-Density Lipoprotein Biogenesis and Functionality.

    Current atherosclerosis reports·2016
    Same author

    Formation of bradykinin from kallidin-10 by aminopeptidase B.

    Nature·2010
    Same author

    Dynamics of apolipoprotein-phospholipid interactions.

    Biophysical journal·2009
    Same author

    Thermodynamics of lipid-protein association in human plasma lipoproteins.

    Biophysical journal·2009
    Same author

    Mechanism of association of human plasma apolipoproteins with dimyristoylphosphatidylcholine: effect of lipid clusters on reaction rates.

    Biophysical journal·2009

    Area of Science:

    • Biochemistry
    • Structural Biology
    • Protein Chemistry

    Background:

    • Polypeptide segments with specific surface topography, termed amphipathic helixes, are proposed as fundamental lipid-associating domains in apolipoproteins.
    • A computational analysis revealed that amyloid A, a protein linked to secondary amyloidosis, also possesses amphipathic helixes.

    Purpose of the Study:

    • To investigate the lipid-binding capabilities of amyloid A protein.
    • To determine if amyloid A's amphipathic helixes mediate spontaneous association with phospholipid vesicles.
    • To explore the structural and functional implications of this interaction.

    Main Methods:

    • Equilibrium density gradient ultracentrifugation to isolate protein-lipid complexes.
    • Circular dichroism spectroscopy to measure changes in alpha helicity.
    • Fluorescence spectroscopy to monitor tryptophan residue environment.
    • Negative stain electron microscopy for visualizing complex morphology.

    Main Results:

    • Amyloid A formed stable complexes with phospholipid vesicles.
    • A significant increase (100%) in alpha helicity was observed upon complex formation.
    • A 9-nm shift in fluorescence maximum indicated tryptophan relocation to a nonpolar environment.
    • Electron microscopy revealed stacked disk-like protein-lipid structures.

    Conclusions:

    • Amyloid A protein directly associates with phospholipid vesicles, driven by its amphipathic helixes.
    • The findings highlight the amphipathic helix as a critical structural motif for lipid-protein interactions.
    • These results offer insights into the potential origin and function of amyloid A protein.

    Related Experiment Videos