HIV-1 matrix-31 membrane binding peptide interacts differently with membranes containing PS vs. PI(4,5)P2.
Biochim Biophys Acta
; 1858(12): 3071-3081, 2016 12.
Article
em En
| MEDLINE
| ID: mdl-27641491
Efficient assembly of HIV-1 at the plasma membrane (PM) of the T-cell specifically requires PI(4,5)P2. It was previously shown that a highly basic region (HBR) of the matrix protein (MA) on the Gag precursor polyprotein Pr55Gag is required for membrane association. MA is N-terminally myristoylated, which enhances its affinity to membranes. In this work we used X-ray scattering and neutron reflectivity to determine how the physical properties and structure of lipid bilayers respond to the addition of binding domain peptides, either in the myristoylated form (MA31myr) or without the myristoyl group (MA31). Neutron reflectivity measurements showed the peptides predominantly located in the hydrocarbon interior. Diffuse X-ray scattering showed differences in membrane properties upon addition of peptides and the direction of the changes depended on lipid composition. The PI(4,5)P2-containing bilayers softened, thinned and became less ordered as peptide concentration increased. In contrast, POPS-containing bilayers with equivalent net charge first stiffened, thickened and became more ordered with increasing peptide concentration. As softening the host cell's PM upon contact with the protein lowers the free energy for membrane restructuring, thereby potentially facilitating budding of viral particles, our results suggest that the role of PI(4,5)P2 in viral assembly goes beyond specific stereochemical membrane binding. These studies reinforce the importance of lipids in virology.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Fosfatidilserinas
/
HIV-1
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Montagem de Vírus
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Fosfatidilinositol 4,5-Difosfato
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Produtos do Gene gag do Vírus da Imunodeficiência Humana
Idioma:
En
Revista:
Biochim Biophys Acta
Ano de publicação:
2016
Tipo de documento:
Article
País de afiliação:
Estados Unidos