Cloaked similarity between HIV-1 and SARS-CoV suggests an anti-SARS strategy

• DOI: 10.1186/1471-2180-3-20
• Publication Date: 2003-10-14T06:24:19Z
• Authors: Yossef Kliger; Erez Y Levanon
• Keywords: 0301 basic medicine; Anti-HIV Agents; Protein Conformation; Molecular Sequence Data; Enfuvirtide; Microbiology; Antiviral Agents; QR1-502; HIV Envelope Protein gp41; Peptide Fragments; 3. Good health; 03 medical and health sciences; Severe acute respiratory syndrome-related coronavirus; Drug Design; HIV-1; Viral Fusion Proteins; Research Article

Severe acute respiratory syndrome (SARS) is a febrile respiratory illness. The disease has been etiologically linked to a novel coronavirus that has been named the SARS-associated coronavirus (SARS-CoV), whose genome was recently sequenced. Since it is a member of the Coronaviridae, its spike protein (S2) is believed to play a central role in viral entry by facilitating fusion between the viral and host cell membranes. The protein responsible for viral-induced membrane fusion of HIV-1 (gp41) differs in length, and has no sequence homology with S2.Sequence analysis reveals that the two viral proteins share the sequence motifs that construct their active conformation. These include (1) an N-terminal leucine/isoleucine zipper-like sequence, and (2) a C-terminal heptad repeat located upstream of (3) an aromatic residue-rich region juxtaposed to the (4) transmembrane segment.This study points to a similar mode of action for the two viral proteins, suggesting that anti-viral strategy that targets the viral-induced membrane fusion step can be adopted from HIV-1 to SARS-CoV. Recently the FDA approved Enfuvirtide, a synthetic peptide corresponding to the C-terminal heptad repeat of HIV-1 gp41, as an anti-AIDS agent. Enfuvirtide and C34, another anti HIV-1 peptide, exert their inhibitory activity by binding to a leucine/isoleucine zipper-like sequence in gp41, thus inhibiting a conformational change of gp41 required for its activation. We suggest that peptides corresponding to the C-terminal heptad repeat of the S2 protein may serve as inhibitors for SARS-CoV entry.