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

A membrane-mediated catalytic event in prothrombin activation

C Kung1, E Hayes, K G Mann

  • 1Department of Biochemistry, University of Vermont College of Medicine, Burlington 05405-0068.

The Journal of Biological Chemistry
|October 14, 1994
PubMed
Summary

Saturated phospholipids significantly reduce prothrombinase activity by impairing catalytic efficiency, not just protein assembly. This indicates the phospholipid membrane is a functional component of the prothrombinase enzyme complex.

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

In vitro formation of hydroxy metabolites of cocaine and amphetamines in hair after hair product exposure.

Journal of analytical toxicology·2025
Same author

Comparison of the mid-infrared spectra and prediction equations developed from morning and evening milk samples from twice-a-day milked dairy cows.

Journal of dairy science·2024
Same author

Sepsis and documentation of six physiological vital signs in GP Out-of-Hours.

Irish medical journal·2023
Same author

Trend analysis and prediction of seasonal changes in milk composition from a pasture-based dairy research herd.

Journal of dairy science·2023
Same author

Assessing the impacts of citizen-led policies on emissions, air quality and health.

Journal of environmental management·2021
Same author

Assessing air pollution in European cities to support a citizen centered approach to air quality management.

The Science of the total environment·2021

Area of Science:

  • Biochemistry
  • Molecular Biology
  • Membrane Biophysics

Background:

  • Prothrombinase assembly occurs on unsaturated phospholipid membranes, facilitating blood coagulation.
  • The role of saturated versus unsaturated phospholipids in prothrombinase function is not fully understood.

Purpose of the Study:

  • To investigate the impact of saturated phosphatidylcholine/phosphatidylserine (PCPS) membranes on prothrombinase assembly, substrate delivery, and catalytic activity.
  • To differentiate the effects of membrane composition on enzyme complex formation and function.

Main Methods:

  • Utilized saturated PCPS (75:25, w/w) vesicles with varying fatty acid chain lengths (C14:0, C16:0, C18:0).
  • Measured prothrombinase activity, protein binding (Kd, n), and kinetic parameters (kon, koff, Km, kcat) using techniques including stopped-flow assays.

Related Experiment Videos

  • Compared results with those obtained from unsaturated PCPS membranes.

    • Main Results:

    • Saturated PCPS membranes caused up to a 20-fold decrease in prothrombinase activity compared to unsaturated membranes.
    • While protein binding capacity was largely maintained, association and dissociation rates (kon, koff) for enzyme components were altered.
    • A significant reduction in catalytic efficiency (kcat) was observed for both prothrombin and prethrombin-1 on saturated membranes, indicating impaired proteolytic activity.

    Conclusions:

    • The reduced prothrombinase activity on saturated phospholipids is primarily due to compromised catalytic efficiency (kcat), not solely altered assembly or substrate delivery.
    • These findings suggest that the phospholipid bilayer is an integral functional component of the prothrombinase enzyme complex, influencing its proteolytic function.