Detection of lipid-induced structural changes of the Marburg virus matrix protein VP40 using hydrogen/deuterium exchange-mass spectrometry.
Marburg virus (MARV) is a lipid-enveloped virus from theFiloviridaefamily containing a negative sense RNA genome. One of the seven MARV genes encodes the matrix protein VP40, which forms a matrix layer beneath the plasma membrane inner leaflet to facilitate budding from the host cell. MARV VP40 (mVP40) has been shown to be a dimeric peripheral protein with a broad and flat basic surface that can associate with anionic phospholipids such as phosphatidylserine. Although a number of mVP40 cationic residues have been shown to facilitate binding to membranes containing anionic lipids, much less is known on how mVP40 assembles to form the matrix layer following membrane binding. Here we have used hydrogen/deuterium exchange (HDX) mass spectrometry to determine the solvent accessibility of mVP40 residues in the absence and presence of phosphatidylserine and phosphatidylinositol 4,5-bisphosphate. HDX analysis demonstrates that two basic loops in the mVP40 C-terminal domain make important contributions to anionic membrane binding and also reveals a potential oligomerization interface in the C-terminal domain as well as a conserved oligomerization interface in the mVP40 N-terminal domain. Lipid binding assays confirm the role of the two basic patches elucidated with HD/X measurements, whereas molecular dynamics simulations and membrane insertion measurements complement these studies to demonstrate that mVP40 does not appreciably insert into the hydrocarbon region of anionic membranes in contrast to the matrix protein from Ebola virus. Taken together, we propose a model by which association of the mVP40 dimer with the anionic plasma membrane facilitates assembly of mVP40 oligomers.
From the Department of Chemistry and Biochemistry, The Eck Institute for Global Health and The Boler-Parseghian Center for Rare and Neglected Diseases, University of Notre Dame, Notre Dame, Indiana 46556.
Kaveesha J
KJ
Wijesinghe
the Department of Medicine, University of California, San Diego, La Jolla, California 92093-0652.
Sarah
S
Urata
the Departments of Physics and.
Nisha
N
Bhattarai
the Department of Biological Sciences, Kent State University, Kent, Ohio 44242, and.
Edgar E
EE
Kooijman
the Departments of Physics and.|Biomolecular Sciences Institute, Florida International University, Miami, Florida 33199.
Bernard S
BS
Gerstman
the Departments of Physics and.|Biomolecular Sciences Institute, Florida International University, Miami, Florida 33199.
Prem P
PP
Chapagain
the Department of Medicine, University of California, San Diego, La Jolla, California 92093-0652, s4li@ucsd.edu.
Sheng
S
Li
From the Department of Chemistry and Biochemistry, The Eck Institute for Global Health and The Boler-Parseghian Center for Rare and Neglected Diseases, University of Notre Dame, Notre Dame, Indiana 46556, rstaheli@iu.edu.|the Department of Biochemistry and Molecular Biology, Indiana University School of Medicine-South Bend, South Bend, Indiana 46617.
Robert V
RV
Stahelin
D041961:Deuterium Exchange Measurement; D029024:Marburgvirus / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D013058:Mass Spectrometry; D008956:Models, Chemical; D010713:Phosphatidylcholines / Q000737:chemistry*; D010718:Phosphatidylserines / Q000737:chemistry*; D055503:Protein Multimerization; D020836:Protein Structure, Quaternary; D014763:Viral Matrix Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism
D010713:Phosphatidylcholines; D010718:Phosphatidylserines; C080981:VP40 protein, virus; D014763:Viral Matrix Proteins; C050294:1-palmitoyl-2-oleoylglycero-3-phosphoserine; C028694:1-palmitoyl-2-oleoylphosphatidylcholine
Ebola virus; Filovirus; Marburg Virus; VP40; hydrogen-deuterium exchange; mass spectrometry (MS); oligomerization; phosphatidylserine; plasma membrane; viral budding