Structure and Function of Viral Fusion Domains

病毒融合域的结构和功能

• 批准号: 6820684
• 负责人: PATRICK W MOBLEY
• 金额: $ 14.64万
• 依托单位: CALIFORNIA STATE POLY U POMONA
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-07-01 至 2008-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6820684
• 关键词: Orthomyxoviridae; amyloid proteins; cell aggregation; circular dichroism; computer simulation; conformation; cytolysis; electron spin resonance spectroscopy; erythrocytes; glycoproteins; health science research support; human immunodeficiency virus; infrared spectrometry; liposomes; molecular dynamics; particle counter; protein purification; protein structure function; virus envelope; virus protein

The fusion of enveloped viruses with their target cells is directed by the viral transmembrane glycoprotein. The first part of this protein to interact with the cellular membrane is called the fusion domain and is a conserved, largely hydrophobic, polymorphic sequence usually near the amino terminus. Site-directed mutagenesis has shown that the replacement of key residues in the fusion domain of influenza virus hemagglutinin (HA2) or HIV glycoprotein 41,000 (gp41) affect viral fusion. Synthetic peptides with the same sequences as these N-terminal regions, termed fusion peptides (FP), induce lipid mixing and lysis of liposomes and cell membranes. Although there is much information on the structure of viral FP, there is little understanding of the relationship of the intramembrane FP structures to their function. The principal objective of the proposed research is to determine the structural characteristics common to viral FP that are necessary for fusion competence. Using FP based on mutated viral sequences, we will seek correlations between their altered activity and membrane-bound structures. We will also further characterize the inhibition of FP by the C-helix (DP-178) or its fragments and we will assess the ability of FP to expand its conformational space to include the formation of amyloid suprastructures. Membrane-perturbing activities of FP and its variants will be screened with erythrocyte lysis and aggregation measured by the absorbance of released hemoglobin at 540nm and cell sizing with a Coulter Counter. Lipid mixing, leakage, and aggregation of synthetic large unilamellar vesicles induced by FP will be measured using fluorescence dequenching and light scattering assays. The conformation, orientation, and topography of fusion peptides in membranes or membrane mimmicking solvents will be examined by circular dichroism (CD), Fourier transform infrared (FTIR), electron spin resonance (ESR) spectroscopy and molecular modeling. Correlations will be sought between the structural models and the fusion activities and lipid perturbations induced by viral fusion peptides and variants.

包膜病毒与靶细胞的融合是由病毒跨膜引导的