A Template-assembled Model of the N-peptide Helix Bundle from HIV-1 Gp-41 with High Affinity for C-peptide

ABSTRACT Binding of the human immunodeficiency virus (HIV) envelope glycoprotein (Env) to the cellular CD4 receptor and a chemokine coreceptor initiates a series of conformational changes in the Env subunits gp120 and gp41. Eventually, the trimeric gp41 folds into a six-helix bundle, thereby inducing fusion of the viral and cellular membranes. C peptides derived from the C-terminal heptad repeat (CHR) of gp41 are efficient entry inhibitors as they block the six-helix bundle formation. Previously, we developed a membrane-anchored C peptide (maC46) expressed from a retroviral vector that also shows high activity against virus strains resistant to enfuvirtide (T-20), an antiviral C peptide approved for clinical use. Here, we present a systematic analysis of mutations in Env that confer resistance of HIV type 1 (HIV-1) to maC46. We selected an HIV-1 BaL strain with 10-fold reduced sensitivity to maC46 (BaL_C46) by passaging virus for nearly 200 days in the presence of gradually increasing concentrations of maC46. In comparison to wild-type BaL, BaL_C46 had five mutations at highly conserved positions in Env, three in gp120, one in the N-terminal heptad-repeat (NHR), and one in the CHR of gp41. No mutations were found in the NHR domain around the GIV motif that are known to cause resistance to enfuvirtide. Instead, maC46 resistance was found to depend on complementary mutations in the NHR and CHR that considerably favor binding of the mutated NHR to the mutated CHR over binding to maC46. In addition, resistance was highly dependent on mutations in gp120 that accelerated entry. Taken together, resistance to maC46 did not develop readily and required multiple cooperating mutations at conserved positions of the viral envelope glycoproteins gp120 and gp41.

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Discovery and Characterization of a Novel CD4-Binding Adnectin with Potent Anti-HIV Activity

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00508-17 ◽

2017 ◽

Vol 61 (8) ◽

Cited By ~ 7

Author(s):

David Wensel ◽

Yongnian Sun ◽

Zhufang Li ◽

Sharon Zhang ◽

Caryn Picarillo ◽

...

Keyword(s):

Conformational Changes ◽

Viral Entry ◽

High Affinity ◽

Glycosylation Sites ◽

Spectrum Activity ◽

Anti Hiv ◽

Hiv 1 ◽

Broad Spectrum Activity

ABSTRACT A novel fibronectin-based protein (Adnectin) HIV-1 inhibitor was generated using in vitro selection. This inhibitor binds to human CD4 with a high affinity (3.9 nM) and inhibits viral entry at a step after CD4 engagement and preceding membrane fusion. The progenitor sequence of this novel inhibitor was selected from a library of trillions of Adnectin variants using mRNA display and then further optimized for improved antiviral and physical properties. The final optimized inhibitor exhibited full potency against a panel of 124 envelope (gp160) proteins spanning 11 subtypes, indicating broad-spectrum activity. Resistance profiling studies showed that this inhibitor required 30 passages (151 days) in culture to acquire sufficient resistance to result in viral titer breakthrough. Resistance mapped to the loss of multiple potential N-linked glycosylation sites in gp120, suggesting that inhibition is due to steric hindrance of CD4-binding-induced conformational changes.

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In Vitro Evolution of Functional Nucleic Acids: High-Affinity RNA Ligands of the HIV-1 rev Protein

The Polymerase Chain Reaction ◽

10.1007/978-1-4612-0257-8_20 ◽

1994 ◽

pp. 233-243 ◽

Cited By ~ 1

Author(s):

Craig Tuerk ◽

Sheela MacDougal-Waugh ◽

Gerald Z. Hertz ◽

Larry Gold

Keyword(s):

Nucleic Acids ◽

In Vitro Evolution ◽

High Affinity ◽

Rna Ligands ◽

Functional Nucleic Acids ◽

Hiv 1 ◽

Rev Protein

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Structural insights into the conformational plasticity of the full-length trimeric HIV-1 envelope glycoprotein precursor

10.1101/288472 ◽

2018 ◽

Author(s):

Shijian Zhang ◽

Wei Li Wang ◽

Shuobing Chen ◽

Maolin Lu ◽

Eden P. Go ◽

...

Keyword(s):

Viral Entry ◽

Envelope Glycoprotein ◽

Structural Data ◽

Full Length ◽

Heptad Repeat ◽

Structural Basis ◽

Glycoprotein Precursor ◽

Helix Bundle ◽

Conformational Plasticity ◽

Hiv 1

SummaryThe human immunodeficiency virus (HIV-1) envelope glycoprotein (Env) trimer mediates viral entry into cells and is the major target for the host antibody response. In infected cells, the mature Env [(gp120/gp41)3] is produced by cleavage of a trimeric gp160 precursor. Proteolytic cleavage decreases Env conformational flexibility, allowing the mature Env to resist antibody binding to conserved elements. The conformational plasticity of the Env precursor skews the humoral immune response towards the elicitation of ineffectual antibodies, contributing to HIV-1 persistence in the infected host. The structural basis for the plasticity of the Env precursor remains elusive. Here we use cryo-electron microscopy to visualize two coexisting conformational states of the full-length Env precursor at nominal resolutions of 5.5 and 8.0 Å. The State-P2 conformation features a three-helix bundle of the gp41 heptad repeat region in the core, but has disordered membrane-interactive regions. State-P1 trimers lack the three-helix bundle and instead retain ordered transmembrane and membrane-proximal external regions embracing a central cavity. Our structural data shed light on the unusual plasticity of the Env precursor and provide new clues to Env immunogen discovery.

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Competitive displacement of full-length HIV-1 Nef from the Hck SH3 domain by a high-affinity artificial peptide

Biological Chemistry ◽

10.1515/bc.2007.075 ◽

2007 ◽

Vol 388 (6) ◽

pp. 611-615 ◽

Cited By ~ 12

Author(s):

Thomas Stangler ◽

Tuyen Tran ◽

Silke Hoffmann ◽

Holger Schmidt ◽

Esther Jonas ◽

...

Keyword(s):

Nmr Spectroscopy ◽

Phage Display ◽

Dissociation Constant ◽

Sh3 Domain ◽

Competitive Displacement ◽

Ligand Interaction ◽

High Affinity ◽

Hematopoietic Cell Kinase ◽

Proline Rich Peptide ◽

Hiv 1

AbstractWe studied the interaction of the artificial 12-aa proline-rich peptide PD1 with the SH3 domain of the hematopoietic cell kinase Hck and the peptide's potency in competitively displacing HIV-1 Nef from the Hck SH3 domain. PD1 was obtained from a phage display screen and exhibits exceptional affinity for the Hck SH3 domain (Kd=0.23 μM). Competition experiments using NMR spectroscopy demonstrate that the peptide even displaces Nef from Hck SH3 and allow for estimation of the Nef-Hck SH3 dissociation constant (Kd=0.44 μM), the strongest SH3 ligand interaction known so far. Consequences of this study for novel antiviral concepts are discussed.

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θ Defensins Protect Cells from Infection by Herpes Simplex Virus by Inhibiting Viral Adhesion and Entry

Journal of Virology ◽

10.1128/jvi.78.10.5147-5156.2004 ◽

2004 ◽

Vol 78 (10) ◽

pp. 5147-5156 ◽

Cited By ~ 147

Author(s):

Bushra Yasin ◽

Wei Wang ◽

Mabel Pang ◽

Natalia Cheshenko ◽

Teresa Hong ◽

...

Keyword(s):

Herpes Simplex ◽

Nuclear Translocation ◽

Temperature Shift ◽

Virus Surface ◽

Herpes Simplex Viruses ◽

Viral Attachment ◽

High Affinity ◽

Simplex Virus ◽

Hiv 1

ABSTRACT We tested the ability of 20 synthetic θ defensins to protect cells from infection by type 1 and type 2 herpes simplex viruses (HSV-1 and -2, respectively). The peptides included rhesus θ defensins (RTDs) 1 to 3, originally isolated from rhesus macaque leukocytes, and three peptides (retrocyclins 1 to 3) whose sequences were inferred from human θ-defensin (DEFT) pseudogenes. We also tested 14 retrocyclin analogues, including the retro, enantio, and retroenantio forms of retrocyclin 1. Retrocyclins 1 and 2 and RTD 3 protected cervical epithelial cells from infection by both HSV serotypes, but only retrocyclin 2 did so without causing cytotoxicity or requiring preincubation with the virus. Surface plasmon resonance studies revealed that retrocyclin 2 bound to immobilized HSV-2 glycoprotein B (gB2) with high affinity (Kd , 13.3 nM) and that it did not bind to enzymatically deglycosylated gB2. Temperature shift experiments indicated that retrocyclin 2 and human α defensins human neutrophil peptide 1 (HNP 1) to HNP 3 protected human cells from HSV-2 by different mechanisms. Retrocyclin 2 blocked viral attachment, and its addition during the binding or penetration phases of HSV-2 infection markedly diminished nuclear translocation of VP16 and expression of ICP4. In contrast, HNPs 1 to 3 had little effect on binding but reduced both VP16 transport and ICP4 expression if added during the postbinding (penetration) period. We recently reported that θ defensins are miniature lectins that bind gp120 of human immunodeficiency virus type 1 (HIV-1) with high affinity and inhibit the entry of R5 and X4 isolates of HIV-1. Given its small size (18 residues), minimal cytotoxicity, lack of activity against vaginal lactobacilli, and effectiveness against both HSV-2 and HIV-1, retrocyclin 2 provides an intriguing prototype for future topical microbicide development.

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