Non-peptide entry inhibitors of HIV-1 that target the gp41 coiled coil pocket (original) (raw)
Related papers
Biochemical and Biophysical Research Communications, 2000
HIV-1 envelope glycoprotein transmembrane subunit gp41 play a critical role in the fusion of viral and target cell membranes. The gp41 C-terminal heptad repeat region interacts with the N-terminal coiled-coil region to form a six-stranded core structure. Peptides derived from gp41 C-terminal heptad repeat region (C-peptides) are potent HIV-1 entry inhibitors by binding to gp41 N-terminal coiled-coil region. Most recently, we have identified two small organic compounds that inhibit HIV-1-mediated membrane fusion by blocking the formation of gp41 core. These two active compounds contain both hydrophobic and acidic groups while the inactive compounds only have hydrophobic groups. Analysis by computer modeling indicate that the acidic groups in the active compounds can form salt bridge with Lys 574 in the N-terminal coiled-coil region of gp41. Asp 632 in a C-peptide can also form a salt bridge with Lys 574. Replacement of Asp 632 with positively charged residues or hydrophobic residues resulted in significant decrease of HIV-1 inhibitory activity. These results suggest that a salt bridge between an N-terminal coiled coil of the gp41 and an antiviral agent targeted to the gp41 core is important for anti-HIV-1 activity.
Discovery of HIV fusion inhibitors targeting gp41 using a comprehensive α-helix mimetic library
Bioorganic & Medicinal Chemistry Letters, 2012
The evaluation of a comprehensive α-helix mimetic library for binding the gp41 NHR hydrophobic pocket recognizing an intramolecular CHR α-helix provided a detailed depiction of structural features required for binding and led to the discovery of small molecule inhibitors (K i 0.6-1.3 µM) that not only match or exceed the potency of those disclosed over the past decade, but that also exhibit effective activity in a cell-cell fusion assay (IC 50 5-8 µM).
Design of potent inhibitors of HIV-1 entry from the gp41 N-peptide region
Proceedings of the National Academy of Sciences of the United States of America, 2001
The HIV-1 gp41 envelope glycoprotein promotes fusion of the virus and cell membranes through the formation of a trimer-of-hairpins structure, in which the amino- and carboxyl-terminal regions of the gp41 ectodomain are brought together. Synthetic peptides derived from these two regions (called N and C peptides, respectively) inhibit HIV-1 entry. In contrast to C peptides, which inhibit in the nanomolar range, N peptides are weak inhibitors with IC(50) values in the micromolar range. To test the hypothesis that the weak inhibition of N peptides results from their tendency to aggregate, we have constructed chimeric variants of the N-peptide region of gp41 in which soluble trimeric coiled coils are fused to portions of the gp41 N peptide. These molecules, which present the N peptide in a trimeric coiled-coil conformation, are remarkably more potent inhibitors than the N peptides themselves and likely target the carboxyl-terminal region of the gp41 ectodomain. The best inhibitors descri...
Amphipathic Properties of HIV-1 gp41 Fusion Inhibitors
Current Topics in Medicinal Chemistry, 2011
Small molecule inhibition of HIV fusion has been an elusive goal, despite years of effort by both pharmaceutical and academic laboratories. In this review, we will discuss the amphipathic properties of both peptide and small molecule inhibitors of gp41-mediated fusion. Many of the peptides and small molecules that have been developed target a large hydrophobic pocket situated within the grooves of the coiled coil, a potential hotspot for inhibiting the trimer of hairpin formation that accompanies fusion. Peptide studies reveal molecular properties required for effective inhibition, including elongated structure and lipophilic or amphiphilic nature. The characteristics of peptides that bind in this pocket provide features that should be considered in small molecule development. Additionally, a novel site for small molecule inhibition of fusion has recently been suggested, involving residues of the loop and fusion peptide. We will review the small molecule structures that have been developed, evidence pointing to their mechanism of action and strategies towards improving their affinity. The data points to the need for a strongly amphiphilic character of the inhibitors, possibly as a means to mediate the membrane -protein interaction that occurs in gp41 in addition to the protein -protein interaction that accompanies the fusion-activating conformational transition.
Journal of Virology, 2008
Human immunodeficiency virus type 1 (HIV-1) entry into the host cell involves a cascade of events and currently represents one of most attractive targets in the search for new antiviral drugs. The fusion-active gp41 core structure is a stable six-helix bundle (6-HB) folded by its trimeric N-terminal heptad repeat (NHR) and C-terminal heptad repeat (CHR). Peptides derived from the CHR region of HIV-1 gp41 are potent fusion inhibitors that target the NHR to block viral and cellular membrane fusion in a dominant negative fashion. However, all CHR peptides reported to date are derived primarily from residues 628 to 673 of gp41; little attention has been paid to the upstream sequence of the pocket binding domain (PBD) in the CHR. Here, we have identified a motif (621QIWNNMT627) located at the upstream region of the gp41 CHR, immediately adjacent to the PBD (628WMEWEREI635). Biophysical characterization demonstrated that this motif is critical for the stabilization of the gp41 6-HB core. ...
Journal of Biological Chemistry, 2002
The pre-hairpin intermediate of gp41 from the human immunodeficiency virus (HIV) is the target for two classes of fusion inhibitors that bind to the C-terminal region or the trimeric coiled-coil of N-terminal helices, thereby preventing formation of the fusogenic trimer of hairpins. Using rational design, two 36-residue peptides, N36 Mut(e,g) and N36 Mut(a,d) , were derived from the parent N36 peptide comprising the N-terminal helix of the gp41 ectodomain (residues 546-581 of HIV-1 envelope), characterized by analytical ultracentrifugation and CD, and assessed for their ability to inhibit HIV fusion using a quantitative vaccinia virus-based fusion assay. N36 Mut(e,g) contains nine amino acid substitutions designed to disrupt interactions with the C-terminal region of gp41 while preserving contacts governing the formation of the trimeric coiled-coil. N36 Mut(a,d) contains nine substitutions designed to block formation of the trimeric coiled-coil but retains residues that interact with the C-terminal region of gp41. N36 Mut(a,d) is monomeric, is largely random coil, does not interact with the C34 peptide derived from the C-terminal region of gp41 (residues 628-661), and does not inhibit fusion. The trimeric coiled-coil structure is therefore a prerequisite for interaction with the C-terminal region of gp41. N36 Mut(e,g) forms a monodisperse, helical trimer in solution, does not interact with C34, and yet inhibits fusion about 50-fold more effectively than the parent N36 peptide (IC 50 ϳ 308 nM versus ϳ16 M). These results indicate that N36 Mut(e,g) acts by disrupting the homotrimeric coiled-coil of N-terminal helices in the prehairpin intermediate to form heterotrimers. Thus N36 Mut(e,g) represents a novel third class of gp41-targeted HIV fusion inhibitor. A quantitative model describing the interaction of N36 Mut(e,g) with the pre-hairpin intermediate is presented.
Approaches for identification of HIV-1 entry inhibitors targeting gp41 pocket
Viruses, 2013
The hydrophobic pocket in the HIV-1 gp41 N-terminal heptad repeat (NHR) domain plays an important role in viral fusion and entry into the host cell, and serves as an attractive target for development of HIV-1 fusion/entry inhibitors. The peptide anti-HIV drug targeting gp41 NHR, T-20 (generic name: enfuvirtide; brand name: Fuzeon), was approved by the U.S. FDA in 2003 as the first HIV fusion/entry inhibitor for treatment of HIV/AIDS patients who fail to respond to the current antiretroviral drugs. However, because T20 lacks the pocket-binding domain (PBD), it exhibits low anti-HIV-1 activity and short half-life. Therefore, several next-generation HIV fusion inhibitory peptides with PBD have been developed. They possess longer half-life and more potent antiviral activity against a broad spectrum of HIV-1 strains, including the T-20-resistant variants. Nonetheless, the clinical application of these peptides is still limited by the lack of oral availability and the high cost of product...
Membrane interactions of the synthetic N-terminal peptide of HIV-1 gp41 and its structural analogs
Biochimica et Biophysica Acta (BBA) - Biomembranes, 1999
Structural and functional studies assessed the membrane actions of the N terminus of HIV-1 glycoprotein 41 000 (gp41). Earlier site-directed mutagenesis has shown that key amino acid changes in this gp41 domain inhibit viral infection and syncytia formation. Here, a synthetic peptide corresponding to the N terminus of gp41 (FP; 23 residues, 519^541), and also FP analogs (FP520V/E with ValCGlu at residue 520; FP527L/R with LeuCArg at 527; FP529F/Y with PheCTyr at 529; and FPCLP1 with FP truncated at 525) incorporating these modifications were prepared. When added to human erythrocytes at physiologic pH, the lytic and aggregating activities of the FP analogs were much reduced over those with the wild-type FP. With resealed human erythrocyte ghosts, the lipid-mixing activities of the FP analogs were also substantially depressed over that with the wild-type FP. Combined with results from earlier studies, theoretical calculations using hydrophobic moment plot analysis and physical experiments using circular dichroism and Fourier transform infrared spectroscopy indicate that the diminished lysis and fusion noted for FP analogs may be due to altered peptide-membrane lipid interactions. These data confirm that the N-terminal gp41 domain plays critical roles in the cytolysis and fusion underlying HIV-cell infection.