Document Detail


Ligand extraction properties of the GM2 activator protein and its interactions with lipid vesicles.
MedLine Citation:
PMID:  19580763     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The GM2 activator protein (GM2AP) is an accessory protein required for the enzymatic conversion of GM2 to GM3 by hydrolases in the lysosomal compartments of cells. Here, GM2AP interactions with lipid vesicles are investigated by sucrose-loaded vesicle sedimentation and gel filtration assays, and the effects of pH and lipid composition on membrane binding and lipid extraction are characterized. The sedimentation experiments allow for facile quantification of the percentage of protein in solution and on the bilayer surface, with detailed analysis of the protein:lipid complex that remains in solution. Optimum binding and ligand extraction is found for pH 4.8 where <15% of the protein remains surface associated regardless of the lipid composition. In addition to extracting GM2, we find that GM2AP readily extracts dansyl-headgroup-labeled lipids as well as other phospholipids from vesicles. The ability of GM2AP to extract dansyl-DHPE from vesicles is altered by pH and the specific ligand GM2. Although the unique endosomal lipid, bis(monoacylglycero)phosphate, is not required for ligand extraction, it does enhance the extraction efficiency of GM2 when cholesterol is present in the vesicles.
Authors:
Yong Ran; Gail E Fanucci
Related Documents :
20867743 - Long-range protein coupling mediated by critical low-energy modes of tubular lipid memb...
19715663 - Asymmetric dipping of bacteriophage m13 coat protein with increasing lipid bilayer thic...
8885843 - Glutathione-dependent pathways of refolding of rnase t1 by oxidation and disulfide isom...
Publication Detail:
Type:  Journal Article; Research Support, N.I.H., Extramural    
Journal Detail:
Title:  Biophysical journal     Volume:  97     ISSN:  1542-0086     ISO Abbreviation:  Biophys. J.     Publication Date:  2009 Jul 
Date Detail:
Created Date:  2009-07-07     Completed Date:  2009-10-13     Revised Date:  2011-09-26    
Medline Journal Info:
Nlm Unique ID:  0370626     Medline TA:  Biophys J     Country:  United States    
Other Details:
Languages:  eng     Pagination:  257-66     Citation Subset:  IM    
Affiliation:
Department of Chemistry, University of Florida, Gainesville, Florida 32611-7200, USA.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Cholesterol / chemistry
Chromatography, Gel
Dansyl Compounds / chemistry
G(M2) Activator Protein / chemistry*
Gangliosides / chemistry
Hydrogen-Ion Concentration
Lipid Bilayers / chemistry
Liposomes / chemistry
Lysophospholipids / chemistry
Models, Chemical
Models, Molecular
Monoglycerides / chemistry
Phosphatidylcholines / chemistry
Phosphatidylethanolamines / chemistry
Phosphatidylglycerols / chemistry
Phospholipids / chemistry*
Spectrometry, Fluorescence
Sucrose
Unilamellar Liposomes / chemistry*
Grant Support
ID/Acronym/Agency:
R01 GM077232-03/GM/NIGMS NIH HHS; R01GM077232/GM/NIGMS NIH HHS
Chemical
Reg. No./Substance:
0/Dansyl Compounds; 0/G(M2) Activator Protein; 0/Gangliosides; 0/Lipid Bilayers; 0/Liposomes; 0/Lysophospholipids; 0/Monoglycerides; 0/Phosphatidylcholines; 0/Phosphatidylethanolamines; 0/Phosphatidylglycerols; 0/Phospholipids; 0/Unilamellar Liposomes; 0/bis(monoacylglyceryl)phosphate; 0/sialogangliosides; 3026-45-7/1,2-dipalmitoyl-3-phosphatidylethanolamine; 57-50-1/Sucrose; 57-88-5/Cholesterol; 6753-55-5/1-palmitoyl-2-oleoylphosphatidylcholine; 81490-05-3/1-palmitoyl-2-oleoylglycero-3-phosphoglycerol
Comments/Corrections

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Fatty Acid Transfer from Yarrowia lipolytica Sterol Carrier Protein 2 to Phospholipid Membranes.
Next Document:  Influence of the charge at d85 on the initial steps in the photocycle of bacteriorhodopsin.