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Title: New Method for Measuring the Anchoring Energy of Strongly-Bound Membrane-Associated Proteins [Method for measuring the anchoring energy of strongly-bound membrane-associated proteins].

Here, we describe a new method to measure the activation energy required to remove a strongly-bound membrane-associated protein from a lipid membrane (anchoring energy). It is based on measuring the rate of release of a liposome-bound protein during centrifugation on a sucrose gradient as a function of time and temperature. The method was used to determine anchoring energy for the soluble dengue virus envelope protein (sE) strongly bound to 80:20 POPC:POPG liposomes at pH 5.5. We also measured the binding energy of sE at the same pH for the initial, predominantly reversible, phase of binding to a 70:30 PC:PG lipid bilayer. The anchoring energy (37 +/- 1.7 kcal/mol, 20% PG) was found to be much larger than the binding energy (7.8 +/- 0.3 kcal/mol for 30% PG, or est. 7.0 kcal/mol for 20% PG). This is consistent with data showing that free sE is a monomer at pH 5.5, but assembles into trimers after associating with membranes. But, trimerization alone is insufficient to account for the observed difference in energies, and we conclude that some energy dissipation occurs during the release process. This new method to determine anchoring energy should be useful to understand the complex interactions of integral monotopicmore » proteins and strongly-bound peripheral membrane proteins with lipid membranes.« less
Authors:
 [1] ;  [1] ;  [2] ;  [3] ;  [4] ;  [2] ;  [1] ;  [3] ;  [5] ;  [5] ;  [6]
  1. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Bioenergy and Defense Technology
  2. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
  3. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Nanobiology
  4. Univ. of South Florida, Tampa, FL (United States). Chemistry
  5. Albert Einstein College of Medicine, Bronx, NY (United States). Dept. of Cell Biology
  6. Univ. of New Mexico, Albuquerque, NM (United States). Center for Biomedical Engineering and Dept. of Chemical and Biological Engineering
Publication Date:
Report Number(s):
SAND2016-2840J
Journal ID: ISSN 0006-3495; PII: S0006349515042745
Grant/Contract Number:
AC04-94AL85000
Type:
Accepted Manuscript
Journal Name:
Biophysical Journal
Additional Journal Information:
Journal Volume: 110; Journal Issue: S1; Journal ID: ISSN 0006-3495
Publisher:
Elsevier
Research Org:
Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
Sponsoring Org:
USDOE National Nuclear Security Administration (NNSA)
Country of Publication:
United States
Language:
English
Subject:
59 BASIC BIOLOGICAL SCIENCES
OSTI Identifier:
1340234