scholarly journals X-ray and EM structures of a natively glycosylated HIV-1 envelope trimer

2017 ◽  
Vol 73 (10) ◽  
pp. 822-828 ◽  
Author(s):  
Harry B. Gristick ◽  
Haoqing Wang ◽  
Pamela J. Bjorkman
Keyword(s):  
Crystal Structures ◽  
Biochemical Characterization ◽  
Complex Type ◽  
Cryo Electron Microscopy ◽  
High Mannose ◽  
Complex Glycans ◽  
Anti Hiv ◽  
Hiv 1 ◽  
Trimeric Envelope

The structural and biochemical characterization of broadly neutralizing anti-HIV-1 antibodies (bNAbs) has been essential in guiding the design of potential vaccines to prevent infection by HIV-1. While these studies have revealed critical mechanisms by which bNAbs recognize and/or accommodate N-glycans on the trimeric envelope glycoprotein (Env), they have been limited to the visualization of high-mannose glycan forms only, since heterogeneity introduced from the presence of complex glycans makes it difficult to obtain high-resolution structures. 3.5 and 3.9 Å resolution crystal structures of the HIV-1 Env trimer with fully processed and native glycosylation were solved, revealing a glycan shield of high-mannose and complex-type N-glycans that were used to define the complete epitopes of two bNAbs. Here, the refinement of the N-glycans in the crystal structures is discussed and comparisons are made with glycan densities in glycosylated Env structures derived by single-particle cryo-electron microscopy.

scholarly journals Characterization of Antiviral Activity of Benzamide Derivative AH0109 against HIV-1 Infection

2013 ◽  
Vol 57 (8) ◽  
pp. 3547-3554 ◽  
Author(s):  
Liyu Chen ◽  
Zhujun Ao ◽  
Kallesh Danappa Jayappa ◽  
Gary Kobinger ◽  
ShuiPing Liu ◽  
...  
Keyword(s):  
Nuclear Import ◽  
Effective Concentration ◽  
Effective Vaccine ◽  
Mechanistic Analysis ◽  
Viral Cdna ◽  
Anti Hiv ◽  
Hiv 1 ◽  
Rapid Emergence ◽  
Infection Experiments

ABSTRACTIn the absence of an effective vaccine against HIV-1 infection, anti-HIV-1 strategies play a major role in disease control. However, the rapid emergence of drug resistance against all currently used anti-HIV-1 molecules necessitates the development of new antiviral molecules and/or strategies against HIV-1 infection. In this study, we have identified a benzamide derivative named AH0109 that exhibits potent anti-HIV-1 activity at an 50% effective concentration of 0.7 μM in HIV-1-susceptible CD4+C8166 T cells. Mechanistic analysis revealed that AH0109 significantly inhibits both HIV-1 reverse transcription and viral cDNA nuclear import. Furthermore, our infection experiments indicated that AH0109 is capable of disrupting the replication of HIV-1 strains that are resistant to the routinely used anti-HIV-1 drugs zidovudine, lamivudine, nevirapine, and raltegravir. Together, these findings provide evidence for a newly identified antiviral molecule that can potentially be developed as an anti-HIV-1 agent.

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

2017 ◽  
Vol 61 (8) ◽  
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.

Biochemical characterization of HIV-1 Rev as a potent activator of casein kinase II in vitro

FEBS Letters ◽  
1998 ◽  
Vol 428 (3) ◽  
pp. 235-240 ◽  
Author(s):  
Kenzo Ohtsuki ◽  
Toshiro Maekawa ◽  
Shigeyoshi Harada ◽  
Atsushi Karino ◽  
Yuko Morikawa ◽  
...  
Keyword(s):  
Biochemical Characterization ◽  
Casein Kinase Ii ◽  
Casein Kinase ◽  
Hiv 1

Characterization of the furin cleavage motif for HIV-1 trimeric envelope glycoprotein by intact LC-MS analysis

The Analyst ◽  
2020 ◽  
Vol 145 (5) ◽  
pp. 1636-1640 ◽  
Author(s):  
Nicole A. Schneck ◽  
Vera B. Ivleva ◽  
Cindy X. Cai ◽  
Jonathan W. Cooper ◽  
Q. Paula Lei
Keyword(s):  
Envelope Glycoprotein ◽  
Mass Measurement ◽  
Furin Cleavage ◽  
Ms Analysis ◽  
Cleavage Motif ◽  
Hiv 1 ◽  
Trimeric Envelope

We demonstrate a rapid deglycosylation strategy for recombinant HIV-1 envelope glycoprotein, enabling intact LC-MS mass measurement and furin cleavage monitoring.

scholarly journals Man-Specific, GalNAc/T/Tn-Specific and Neu5Ac-Specific Seaweed Lectins as Glycan Probes for the SARS-CoV-2 (COVID-19) Coronavirus

Marine Drugs ◽  
2020 ◽  
Vol 18 (11) ◽  
pp. 543
Author(s):  
Annick Barre ◽  
Els J.M. Van Damme ◽  
Mathias Simplicien ◽  
Hervé Benoist ◽  
Pierre Rougé
Keyword(s):  
Influenza Virus ◽  
Antiviral Agents ◽  
Host Cells ◽  
Carbohydrate Binding ◽  
Complex Type ◽  
Enveloped Viruses ◽  
High Mannose ◽  
Hiv 1 ◽  
Biomedical Interest

Seaweed lectins, especially high-mannose-specific lectins from red algae, have been identified as potential antiviral agents that are capable of blocking the replication of various enveloped viruses like influenza virus, herpes virus, and HIV-1 in vitro. Their antiviral activity depends on the recognition of glycoprotein receptors on the surface of sensitive host cells—in particular, hemagglutinin for influenza virus or gp120 for HIV-1, which in turn triggers fusion events, allowing the entry of the viral genome into the cells and its subsequent replication. The diversity of glycans present on the S-glycoproteins forming the spikes covering the SARS-CoV-2 envelope, essentially complex type N-glycans and high-mannose type N-glycans, suggests that high-mannose-specific seaweed lectins are particularly well adapted as glycan probes for coronaviruses. This review presents a detailed study of the carbohydrate-binding specificity of high-mannose-specific seaweed lectins, demonstrating their potential to be used as specific glycan probes for coronaviruses, as well as the biomedical interest for both the detection and immobilization of SARS-CoV-2 to avoid shedding of the virus into the environment. The use of these seaweed lectins as replication blockers for SARS-CoV-2 is also discussed.

scholarly journals Structure and mechanism of CutA, RNA nucleotidyl transferase with an unusual preference for cytosine

2020 ◽  
Vol 48 (16) ◽  
pp. 9387-9405
Author(s):  
Deepshikha Malik ◽  
Kamil Kobyłecki ◽  
Paweł Krawczyk ◽  
Jarosław Poznański ◽  
Aleksandra Jakielaszek ◽  
...  
Keyword(s):  
Crystal Structures ◽  
Aspergillus Nidulans ◽  
Dynamic Process ◽  
Biochemical Characterization ◽  
Catalytic Core ◽  
Rna Molecules ◽  
Conformational Dynamic ◽  
Nucleotidyl Transferase ◽  
Preferential Binding

Abstract Template-independent terminal ribonucleotide transferases (TENTs) catalyze the addition of nucleotide monophosphates to the 3′-end of RNA molecules regulating their fate. TENTs include poly(U) polymerases (PUPs) with a subgroup of 3′ CUCU-tagging enzymes, such as CutA in Aspergillus nidulans. CutA preferentially incorporates cytosines, processively polymerizes only adenosines and does not incorporate or extend guanosines. The basis of this peculiar specificity remains to be established. Here, we describe crystal structures of the catalytic core of CutA in complex with an incoming non-hydrolyzable CTP analog and an RNA with three adenosines, along with biochemical characterization of the enzyme. The binding of GTP or a primer with terminal guanosine is predicted to induce clashes between 2-NH2 of the guanine and protein, which would explain why CutA is unable to use these ligands as substrates. Processive adenosine polymerization likely results from the preferential binding of a primer ending with at least two adenosines. Intriguingly, we found that the affinities of CutA for the CTP and UTP are very similar and the structures did not reveal any apparent elements for specific NTP binding. Thus, the properties of CutA likely result from an interplay between several factors, which may include a conformational dynamic process of NTP recognition.

scholarly journals Characterization of Co-Formulated High-Concentration Broadly Neutralizing Anti-HIV-1 Monoclonal Antibodies for Subcutaneous Administration

Antibodies ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 36
Author(s):  
Vaneet K. Sharma ◽  
Bijay Misra ◽  
Kevin T. McManus ◽  
Sreenivas Avula ◽  
Kaliappanadar Nellaiappan ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Clinical Investigation ◽  
Total Concentration ◽  
Subcutaneous Administration ◽  
Analytical Techniques ◽  
Neutralizing Antibody ◽  
High Concentration ◽  
Anti Hiv ◽  
Hiv 1

The discovery of numerous potent and broad neutralizing antibodies (bNAbs) against Human Immunodeficiency Virus type 1 (HIV-1) envelope glycoprotein has invigorated the potential of using them as an effective preventative and therapeutic agent. The majority of the anti-HIV-1 antibodies, currently under clinical investigation, are formulated singly for intra-venous (IV) infusion. However, due to the high degree of genetic variability in the case of HIV-1, a single broad neutralizing antibody will likely not be sufficient to protect against the broad range of viral isolates. To that end, delivery of two or more co-formulated bnAbs against HIV-1 in a single subcutaneous (SC) injection is highly desired. We, therefore, co-formulated two anti-HIV bnAbs, 3BNC117-LS and 10-1074-LS, to a total concentration of 150 mg/mL for SC administration and analyzed them using a panel of analytical techniques. Chromatographic based methods, such as RP-HPLC, CEX-HPLC, SEC-HPLC, were developed to ensure separation and detection of each antibody in the co-formulated sample. In addition, we used a panel of diverse pseudoviruses to detect the functionality of individual antibodies in the co-formulation. We also used these methods to test the stability of the co-formulated antibodies and believe that such an approach can support future efforts towards the formulation and characterization of multiple high-concentration antibodies for SC delivery.

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