Journal
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
Volume 103, Issue 18, Pages 6871-6876Publisher
NATL ACAD SCIENCES
DOI: 10.1073/pnas.0602213103
Keywords
adiposomes; oil bodies; protein stabilization of fat droplets; surface activity; surface elasticity
Categories
Funding
- NHLBI NIH HHS [2P01 HL26335-21, P01 HL026335] Funding Source: Medline
Ask authors/readers for more resources
Apolipoprotein B (apoB) is one of a unique group of proteins that form and bind to fat droplets, stabilize the emulsified fat, and direct their metabolism. ApoB, secreted on lipoproteins (emulsions), remains bound during lipid metabolism yet exhibits conformational flexibility. It has amphipathic beta-strand (APS)-rich domains and amphipathic alpha-helix (A alpha H)-rich domains. We showed that two consensus APS peptides of apoB bound strongly to hydrophobic interfaces [triolein/water (TO/W) and dodecane/water], were elastic, and were not pushed off the interface when the surface was compressed. In contrast, an AaH peptide modeling helical parts of apoB was forced off the TO/W interface by compression and readsorbed when the interface was expanded. In this report, the surface behavior of apoB-100 was studied at the TO/W interface. Solubilized apoB lowered the interfacial tension of TO/W in a concentration-dependent fashion. At equilibrium tension, if the surface was compressed, part of apoB was pushed off but quickly readsorbed when the surface was expanded. Even when the surface area was compressed by approximate to 55%, part of the apoB molecule remained bound. The maximum surface pressure that apoB could withstand without being partially ejected was 13 mN/m. ApoB showed high elasticity at the TO/W interface. Based on studies of the consensus A beta S and A alpha H peptides, we suggest that A beta Ss anchor apoB and are its nonexchangeable motif, whereas its conformational flexibility arises from both the elastic nature of the APS and the ability of AaH domains of the molecule to desorb and readsorb rapidly in response to surface pressure changes.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available