Lipid composition of viral envelopes is usually rich in sphingolipids and cholesterol (CHOL). These components have a stiffening effect on the membrane, thus enhancing the energetic barrier to be overcome for its fusion with the T-cell plasma membrane, a fundamental step of the infection process. In this work, we demonstrate that the octapeptide (C8) corresponding to the Trp770–Ile777 sequence of the Feline Immunodeficiency Virus gp36 is highly effective in inducing the fusion of palmitoyl oleoyl phosphatidylcholine (POPC)/sphingomyelin (SM)/CHOL membranes. We analyze the molecular mechanism of the C8–membrane interactions combining Neutron Reflectivity (NR) and Electron Spin Resonance (ESR) experiments, and molecular dynamics simulations. A strict interplay among the different lipids in the peptide-induced fusion mechanism is highlighted. Since CHOL preferentially locates close to SM, POPC molecules remain relatively free to interact with the peptide, driving its positioning at the membrane interface. Here, C8 comes in contact with CHOL-interacting SM molecules, causing a strong perturbation of acyl chain ordering, which is a necessary condition for membrane fusion. Our findings suggest that CHOL rules, by an indirect mechanism, the activity of viral fusion glycoproteins.
Cholesterol modulates membrane fusion operated by immunodeficiency viruses / Vitiello, Giuseppe; G., Fragneto; A. A., Petruk; Falanga, Annarita; Galdiero, Stefania; A., D'Ursi; Merlino, Antonello; D'Errico, Gerardino. - In: SOFT MATTER. - ISSN 1744-683X. - 28:9(2013), pp. 6442-6456. [10.1039/C3SM50553G]
Cholesterol modulates membrane fusion operated by immunodeficiency viruses
VITIELLO, GIUSEPPE;FALANGA, ANNARITA;GALDIERO, STEFANIA;MERLINO, ANTONELLO;D'ERRICO, GERARDINO
2013
Abstract
Lipid composition of viral envelopes is usually rich in sphingolipids and cholesterol (CHOL). These components have a stiffening effect on the membrane, thus enhancing the energetic barrier to be overcome for its fusion with the T-cell plasma membrane, a fundamental step of the infection process. In this work, we demonstrate that the octapeptide (C8) corresponding to the Trp770–Ile777 sequence of the Feline Immunodeficiency Virus gp36 is highly effective in inducing the fusion of palmitoyl oleoyl phosphatidylcholine (POPC)/sphingomyelin (SM)/CHOL membranes. We analyze the molecular mechanism of the C8–membrane interactions combining Neutron Reflectivity (NR) and Electron Spin Resonance (ESR) experiments, and molecular dynamics simulations. A strict interplay among the different lipids in the peptide-induced fusion mechanism is highlighted. Since CHOL preferentially locates close to SM, POPC molecules remain relatively free to interact with the peptide, driving its positioning at the membrane interface. Here, C8 comes in contact with CHOL-interacting SM molecules, causing a strong perturbation of acyl chain ordering, which is a necessary condition for membrane fusion. Our findings suggest that CHOL rules, by an indirect mechanism, the activity of viral fusion glycoproteins.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.