Rational Development of β-Peptide Inhibitors of Human Cytomegalovirus Entry

English, Emily P.; Chumanov, Robert S.; Gellman, Samuel H.; Compton, Teresa

doi:10.1074/jbc.m508485200

Cited by 103 publications

(67 citation statements)

References 42 publications

(47 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The results reported here represent a substantial advance relative to earlier efforts to develop unnatural oligomers that mimic ␣-helices involved in protein-protein recognition events (13,14,28,(41)(42)(43)(44)(45)(46). Previous work has been limited to relatively short ␣-helical targets, typically only two to four helical turns.…”

Section: Discussionmentioning

confidence: 76%

Structural and biological mimicry of protein surface recognition by α/β-peptide foldamers

Horne

Johnson

Ketas

et al. 2009

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

254

269

View full text Add to dashboard Cite

Unnatural oligomers that can mimic protein surfaces offer a potentially useful strategy for blocking biomedically important proteinprotein interactions. Here we evaluate an approach based on combining ␣-and ␤-amino acid residues in the context of a polypeptide sequence from the HIV protein gp41, which represents an excellent testbed because of the wealth of available structural and biological information. We show that ␣/␤-peptides can mimic structural and functional properties of a critical gp41 subunit. Physical studies in solution, crystallographic data, and results from cell-fusion and virusinfectivity assays collectively indicate that the gp41-mimetic ␣/␤-peptides effectively block HIV-cell fusion via a mechanism comparable to that of gp41-derived ␣-peptides. An optimized ␣/␤-peptide is far less susceptible to proteolytic degradation than is an analogous ␣-peptide. Our findings show how a two-stage design approach, in which sequence-based ␣3␤ replacements are followed by site-specific backbone rigidification, can lead to physical and biological mimicry of a natural biorecognition process.alpha/beta-peptides ͉ HIV ͉ protein folding ͉ protein-protein interactions I dentification of strategies for interference with specific biopolymer recognition processes constitutes a fundamental challenge. Protein-protein associations are often resistant to inhibition by small molecules because the contact surfaces on the natural partners are large (1). Current clinical approaches to inhibiting proteinprotein interactions that underlie viral infection or aberrant signaling at the cell surface are based on the use of medium-length peptides or proteins (2). It would be valuable to identify alternative sources of antagonists for this type of protein recognition event.Here we show that peptide-like oligomers with unnatural backbones can function as potent antiviral agents by blocking a key protein-protein interaction. The design strategy we employ may prove general for ␣-helix mimicry.The HIV membrane protein gp41 mediates viral envelope-host cell membrane fusion, an essential step in the viral infection cycle. During HIV cell entry, the N-terminal fusion segment of trimeric gp41 inserts into the host cell membrane (3). A profound structural rearrangement of gp41 ensues, driven by formation of an antiparallel six-helix bundle (4-6), which leads to juxtaposition of the viral and host cell membranes. The prehairpin fusion intermediate is composed of three copies of gp41 in an extended conformation. The so-called ''class I'' fusion mechanism used by HIV is common to a variety of enveloped viruses, including those responsible for influenza, Ebola, and SARS (7,8). A number of ␣-peptides based on sequences from the gp41 N-terminal heptad repeat (NHR) domain or C-heptad repeat (CHR) domain (e.g., Fig. 1B, 1 and 2) have been investigated as anti-HIV agents (9, 10). These compounds are thought to act by binding to a gp41 prehairpin intermediate, thereby preventing six-helix bundle formation and subsequent virus-cell fusion. The drug enfu...

show abstract

Section: Discussionmentioning

confidence: 76%

Structural and biological mimicry of protein surface recognition by α/β-peptide foldamers

Horne

Johnson

Ketas

et al. 2009

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

254

269

View full text Add to dashboard Cite

show abstract

“…A ␤-peptide that does not block HCMV infection was used as a control. The inhibitory ␤-peptide displays a high degree of specificity for HCMV, as it does not block entry of mouse CMV or HSV-1 (57). Pretreatment of cells with gB-DLD resulted in a 92% decrease in virus infection as assessed by the HCMV-IE2 GFP reporter virus (Fig.…”

Section: Hcmv Entry Inhibitors Block Hcmv-induced Ifn Signaling But Nmentioning

confidence: 99%

“…The anti-P56 Ab was a gift from G. Sen (The Cleveland Clinic Foundation, Cleveland, OH) (56). The second generation ␤-peptide 19, a potent inhibitor of HCMV entry (57), is designated ␤-peptide (ϩ) in this study, and a control ␤-peptide that does not block HCMV entry is designated ␤-peptide (Ϫ).…”

Section: Reagents and Absmentioning

confidence: 99%

Differential Initiation of Innate Immune Responses Induced by Human Cytomegalovirus Entry into Fibroblast Cells

Juckem

Boehme

Feire

et al. 2008

The Journal of Immunology

Self Cite

View full text Add to dashboard Cite

Infection of permissive fibroblasts with human CMV (HCMV, AD169) is accompanied by a robust activation of innate immune defense. In this study, we show that inflammatory cytokine (IC) secretion and activation of the type I IFN pathway (αβ IFN) are initiated through distinct mechanisms. HCMV is recognized by TLR2 leading to the NF-κB activation and IC secretion. However, the IFN response to HCMV is not a TLR2-dependent process, as a dominant negative TLR2 does not affect the antiviral response to infection. Additionally, bafilomycin, an endosomal acidification inhibitor, has no effect on HCMV-induced IFN responses suggesting that IFN signaling is independent of endosomal resident TLRs. By contrast, disruption of lipid rafts by depletion of cellular cholesterol inhibits both HCMV entry as well as IFN responses. Cholesterol depletion had no effect on the induction of ICs by HCMV, illustrating a biological distinction at the cellular level with the initiation of innate immune pathways. Furthermore, HCMV entry inhibitors block IFN responses but not IC signaling. In particular, blocking the interaction of HCMV with β1 integrin diminished IFN signaling, suggesting that this virus-cell interaction or subsequent downstream steps in the entry pathway are critical for downstream signal transduction events. These data show that HCMV entry and IFN signaling are coordinated processes that require cholesterol-rich microdomains, whereas IC signaling is activated through outright sensing via TLR2. These findings further highlight the complexity and sophistication of innate immune responses at the earliest points in HCMV infection.

show abstract

“…21,22,24 Larger mixedsequence peptides containing both α-and β-amino acids have also shown success as protein ligands for the BH3 recognition site of Bcl-x L . 25,26 Several strategies have been pursued to identify β-peptides that assemble into discrete, wellfolded quaternary structures whose thermodynamic properties resemble those of natural proteins. Remarkably, as early as 1998, Clark et al showed that cyclic β 3 -peptides designed to self-assemble in lipid bilayers supported K + conductance, although the existence of higherorder structure was not investigated.…”

Section: Introductionmentioning

confidence: 99%

Biophysical and Structural Characterization of a Robust Octameric β-Peptide Bundle

et al. 2007

View full text Add to dashboard Cite

Proteins composed of α-amino acids are essential components of the machinery required for life. Stanley Miller's renowned electric discharge experiment provided evidence that an environment of methane, ammonia, water, and hydrogen was sufficient to produce α-amino acids. This reaction also generated other potential protein building blocks such as the β-amino acid β-glycine (also known as β-alanine); however, the potential of these species to form complex ordered structures that support functional roles has not been widely investigated. In this report we apply a variety of biophysical techniques, including circular dichroism, differential scanning calorimetry, analytical ultracentrifugation, NMR and X-ray crystallography, to characterize the oligomerization of two 12-mer β 3 -peptides, Acid-1Y and Acid-1Y*. Like the previously reported β 3 -peptide Zwit-1F, Acid-1Y and Acid-1Y* fold spontaneously into discrete, octameric quaternary structures that we refer to as β-peptide bundles. Surprisingly, the Acid-1Y octamer is more stable than the analogous Zwit-1F octamer, in terms of both its thermodynamics and kinetics of unfolding. The structure of Acid-1Y, reported here to 2.3 Å resolution, provides intriguing hypotheses for the increase in stability. To summarize, in this work we provide additional evidence that nonnatural β-peptide oligomers can assemble into cooperatively folded structures with potential application in enzyme design, and as medical tools and nanomaterials. Furthermore, these studies suggest that nature's selection of α-amino acid precursors was not based solely on their ability to assemble into stable oligomeric structures.

show abstract

Rational Development of β-Peptide Inhibitors of Human Cytomegalovirus Entry

Cited by 103 publications

References 42 publications

Structural and biological mimicry of protein surface recognition by α/β-peptide foldamers

Structural and biological mimicry of protein surface recognition by α/β-peptide foldamers

Differential Initiation of Innate Immune Responses Induced by Human Cytomegalovirus Entry into Fibroblast Cells

Biophysical and Structural Characterization of a Robust Octameric β-Peptide Bundle

Contact Info

Product

Resources

About