Interaction of Peptides with Sequences from the Newcastle Disease Virus Fusion Protein Heptad Repeat Regions

Abstract

Typical of many viral fusion proteins, the sequence of the Newcastle disease virus (NDV) fusion protein has several heptad repeat regions. One, HR1, is located just carboxyl terminal to the fusion peptide, while the other, HR2, is located adjacent to the transmembrane domain. The structure and function of a synthetic peptide with a sequence from the region of the NDV HR1 region (amino acids 150 to 173) were characterized. The peptide inhibited fusion with a half-maximal concentration of approximately 2 μM; however, inhibition was observed only if the peptide was added prior to protease activation of the fusion protein. This inhibition was virus specific since the peptide had minimal effect on fusion directed by the Sendai virus glycoproteins. To explore the mechanism of action, the potential HR1 peptide interaction with a previously characterized fusion inhibitory peptide with a sequence from the HR2 domain (J. K. Young, R. P. Hicks, G. E. Wright, and T. G. Morrison, Virology 238:291–304, 1997) was characterized. The results demonstrated an interaction between the two peptides both functionally and directly. First, while the individual peptides each inhibit fusion, equimolar mixtures of the two peptides had minimal effect on fusion, suggesting that the two peptides form a complex preventing their interaction with a target protein. Second, an HR2 peptide covalently linked with biotin was found to bind specifically to HR1 peptide in a Western blot. The structure of the HR1 peptide was analyzed by nuclear magnetic resonance spectroscopy and found to be an α helix.

Paramyxovirus F1 protein has two fusion peptides: implications for the mechanism of membrane fusion 1 1Edited by A. R.Fersht

“…Recently, it has been shown that both the Nterminal and the C-terminal heptad repeats of the Sendai virus fusion protein, which form a strong complex in solution (Ghosh et al, 1998), dissociate into a-helical monomers upon binding to membranes (Ben-Efraim et al, 1999). In agreement with these observations, NMR studies showed that the N-terminal heptad repeat of the homologous Newcastle disease virus fusion protein has an a-helical structure in SDS, consistent with the notion that it binds parallel with the bilayer, as a monomer, with its hydrophobic face buried in the membrane (Young et al, 1999). Furthermore, the N-terminal heptad repeat of the Sendai virus F1 protein, located between the N-terminal fusion peptide and SV-208, has been shown to assist the N-terminal fusion peptide in inducing membrane fusion (Ghosh & Shai, 1999).…”

Entry of Newcastle Disease Virus into the host cell: Role of acidic pH and endocytosis

“…Monolayers of cells were infected with 1 moi of NDV for 1 h at 37°C. At 7 h post-infection, viral F proteins were activated by digestion with acetyl trypsin [33]. Then, cells were incubated in complete medium overnight and stained with Giemsa or crystal violet for syncytium observation.…”

Inhibition of severe acute respiratory syndrome-associated coronavirus (SARS-CoV) infectivity by peptides analogous to the viral spike protein

“…For example, analogs of the orthomyxovirus, paramyxovirus (Richardson et al, 1980) and HIV-1 fusion peptide domains (Gallaher et al, 1992;Owens et al, 1990;Silburn et al, 1998) block viral infection, presumably by forming inactive heteroaggregates. Likewise, peptides analogous to the HR regions of the HIV-1 (Gallaher et al, 1992;Qureshi et al, 1990;Wild et al, 1992Wild et al, , 1993, paramyxovirus (Lambert et al, 1996;Young et al, 1999) or Ebola virus (EboV) (Watanabe et al, 2000) class I viral fusion proteins block virion infectivity by preventing the transition of the fusion protein into the six-helix bundle state. The anti-HIV-1 peptidic drug Fuzeon TM (DP178, T-20 or enfuvirtide), which overlaps HR2 and the aromatic domain of gp41, was the first of a new class of fusion inhibitor antivirals to gain FDA approval (2003).…”