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1.
Cell Mol Life Sci ; 80(6): 151, 2023 May 17.
Article in English | MEDLINE | ID: covidwho-2325328

ABSTRACT

Antimicrobial peptides (AMPs) are major components of the innate immune defense. Accumulating evidence suggests that the antibacterial activity of many AMPs is dependent on the formation of amyloid-like fibrils. To identify novel fibril forming AMPs, we generated a spleen-derived peptide library and screened it for the presence of amyloidogenic peptides. This approach led to the identification of a C-terminal 32-mer fragment of alpha-hemoglobin, termed HBA(111-142). The non-fibrillar peptide has membranolytic activity against various bacterial species, while the HBA(111-142) fibrils aggregated bacteria to promote their phagocytotic clearance. Further, HBA(111-142) fibrils selectively inhibited measles and herpes viruses (HSV-1, HSV-2, HCMV), but not SARS-CoV-2, ZIKV and IAV. HBA(111-142) is released from its precursor by ubiquitous aspartic proteases under acidic conditions characteristic at sites of infection and inflammation. Thus, HBA(111-142) is an amyloidogenic AMP that may specifically be generated from a highly abundant precursor during bacterial or viral infection and may play an important role in innate antimicrobial immune responses.


Subject(s)
COVID-19 , Zika Virus Infection , Zika Virus , Humans , Peptides , Amyloid/chemistry , Anti-Bacterial Agents/pharmacology , Hemoglobins
2.
Pharmacol Rev ; 75(2): 263-308, 2023 03.
Article in English | MEDLINE | ID: covidwho-2245093

ABSTRACT

Lysine-selective molecular tweezers (MTs) are supramolecular host molecules displaying a remarkably broad spectrum of biologic activities. MTs act as inhibitors of the self-assembly and toxicity of amyloidogenic proteins using a unique mechanism. They destroy viral membranes and inhibit infection by enveloped viruses, such as HIV-1 and SARS-CoV-2, by mechanisms unrelated to their action on protein self-assembly. They also disrupt biofilm of Gram-positive bacteria. The efficacy and safety of MTs have been demonstrated in vitro, in cell culture, and in vivo, suggesting that these versatile compounds are attractive therapeutic candidates for various diseases, infections, and injuries. A lead compound called CLR01 has been shown to inhibit the aggregation of various amyloidogenic proteins, facilitate their clearance in vivo, prevent infection by multiple viruses, display potent anti-biofilm activity, and have a high safety margin in animal models. The inhibitory effect of CLR01 against amyloidogenic proteins is highly specific to abnormal self-assembly of amyloidogenic proteins with no disruption of normal mammalian biologic processes at the doses needed for inhibition. Therapeutic effects of CLR01 have been demonstrated in animal models of proteinopathies, lysosomal-storage diseases, and spinal-cord injury. Here we review the activity and mechanisms of action of these intriguing compounds and discuss future research directions. SIGNIFICANCE STATEMENT: Molecular tweezers are supramolecular host molecules with broad biological applications, including inhibition of abnormal protein aggregation, facilitation of lysosomal clearance of toxic aggregates, disruption of viral membranes, and interference of biofilm formation by Gram-positive bacteria. This review discusses the molecular and cellular mechanisms of action of the molecular tweezers, including the discovery of distinct mechanisms acting in vitro and in vivo, and the application of these compounds in multiple preclinical disease models.


Subject(s)
Biological Products , COVID-19 , Animals , Organophosphates/pharmacology , SARS-CoV-2 , Amyloidogenic Proteins , Mammals
3.
J Med Virol ; 2022 Sep 03.
Article in English | MEDLINE | ID: covidwho-2236944

ABSTRACT

Host cell proteases such as TMPRSS2 are critical determinants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) tropism and pathogenesis. Here, we show that antithrombin (AT), an endogenous serine protease inhibitor regulating coagulation, is a broad-spectrum inhibitor of coronavirus infection. Molecular docking and enzyme activity assays demonstrate that AT binds and inhibits TMPRSS2, a serine protease that primes the Spike proteins of coronaviruses for subsequent fusion. Consequently, AT blocks entry driven by the Spikes of SARS-CoV, MERS-CoV, hCoV-229E, SARS-CoV-2 and its variants of concern including Omicron, and suppresses lung cell infection with genuine SARS-CoV-2. Thus, AT is an endogenous inhibitor of SARS-CoV-2 that may be involved in COVID-19 pathogenesis. We further demonstrate that activation of AT by anticoagulants, such as heparin or fondaparinux, increases the anti-TMPRSS2 and anti-SARS-CoV-2 activity of AT, suggesting that repurposing of native and activated AT for COVID-19 treatment should be explored.

4.
JACS Au ; 2(9): 2187-2202, 2022 Sep 26.
Article in English | MEDLINE | ID: covidwho-2050266

ABSTRACT

The COVID-19 pandemic caused by SARS-CoV-2 presents a global health emergency. Therapeutic options against SARS-CoV-2 are still very limited but urgently required. Molecular tweezers are supramolecular agents that destabilize the envelope of viruses resulting in a loss of viral infectivity. Here, we show that first-generation tweezers, CLR01 and CLR05, disrupt the SARS-CoV-2 envelope and abrogate viral infectivity. To increase the antiviral activity, a series of 34 advanced molecular tweezers were synthesized by insertion of aliphatic or aromatic ester groups on the phosphate moieties of the parent molecule CLR01. A structure-activity relationship study enabled the identification of tweezers with a markedly enhanced ability to destroy lipid bilayers and to suppress SARS-CoV-2 infection. Selected tweezer derivatives retain activity in airway mucus and inactivate the SARS-CoV-2 wildtype and variants of concern as well as respiratory syncytial, influenza, and measles viruses. Moreover, inhibitory activity of advanced tweezers against respiratory syncytial virus and SARS-CoV-2 was confirmed in mice. Thus, potentiated tweezers are broad-spectrum antiviral agents with great prospects for clinical development to combat highly pathogenic viruses.

5.
Nat Commun ; 12(1): 1726, 2021 03 19.
Article in English | MEDLINE | ID: covidwho-1142436

ABSTRACT

SARS-CoV-2 is a respiratory pathogen and primarily infects the airway epithelium. As our knowledge about innate immune factors of the respiratory tract against SARS-CoV-2 is limited, we generated and screened a peptide/protein library derived from bronchoalveolar lavage for inhibitors of SARS-CoV-2 spike-driven entry. Analysis of antiviral fractions revealed the presence of α1-antitrypsin (α1AT), a highly abundant circulating serine protease inhibitor. Here, we report that α1AT inhibits SARS-CoV-2 entry at physiological concentrations and suppresses viral replication in cell lines and primary cells including human airway epithelial cultures. We further demonstrate that α1AT binds and inactivates the serine protease TMPRSS2, which enzymatically primes the SARS-CoV-2 spike protein for membrane fusion. Thus, the acute phase protein α1AT is an inhibitor of TMPRSS2 and SARS-CoV-2 entry, and may play an important role in the innate immune defense against the novel coronavirus. Our findings suggest that repurposing of α1AT-containing drugs has prospects for the therapy of COVID-19.


Subject(s)
COVID-19 Drug Treatment , SARS-CoV-2/drug effects , Serine Endopeptidases/metabolism , Serine Proteinase Inhibitors/pharmacology , alpha 1-Antitrypsin/pharmacology , Antibodies, Viral/blood , Antiviral Agents/pharmacology , COVID-19/blood , Caco-2 Cells , Humans , Immunoglobulin G/blood , Molecular Docking Simulation , Spike Glycoprotein, Coronavirus/metabolism , Virus Internalization/drug effects , Virus Replication/drug effects
6.
Adv Drug Deliv Rev ; 167: 47-65, 2020 12.
Article in English | MEDLINE | ID: covidwho-921794

ABSTRACT

To date, no effective vaccines or therapies are available against the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative pandemic agent of the coronavirus disease 2019 (COVID-19). Due to their safety, efficacy and specificity, peptide inhibitors hold great promise for the treatment of newly emerging viral pathogens. Based on the known structures of viral proteins and their cellular targets, antiviral peptides can be rationally designed and optimized. The resulting peptides may be highly specific for their respective targets and particular viral pathogens or exert broad antiviral activity. Here, we summarize the current status of peptides inhibiting SARS-CoV-2 entry and outline the strategies used to design peptides targeting the ACE2 receptor or the viral spike protein and its activating proteases furin, transmembrane serine protease 2 (TMPRSS2), or cathepsin L. In addition, we present approaches used against related viruses such as SARS-CoV-1 that might be implemented for inhibition of SARS-CoV-2 infection.


Subject(s)
Antiviral Agents/administration & dosage , COVID-19 Drug Treatment , COVID-19/metabolism , Peptide Fragments/administration & dosage , SARS-CoV-2/drug effects , SARS-CoV-2/metabolism , Amino Acid Sequence , Angiotensin-Converting Enzyme 2/antagonists & inhibitors , Angiotensin-Converting Enzyme 2/metabolism , Antiviral Agents/chemistry , Antiviral Agents/metabolism , Drug Delivery Systems/methods , Humans , Peptide Fragments/chemistry , Peptide Fragments/metabolism , Protein Binding/drug effects , Protein Binding/physiology , Protein Structure, Secondary , Protein Structure, Tertiary , Serine Endopeptidases/metabolism , Serine Proteinase Inhibitors/administration & dosage , Serine Proteinase Inhibitors/chemistry , Serine Proteinase Inhibitors/metabolism
7.
J Am Chem Soc ; 142(40): 17024-17038, 2020 10 07.
Article in English | MEDLINE | ID: covidwho-772998

ABSTRACT

Broad-spectrum antivirals are powerful weapons against dangerous viruses where no specific therapy exists, as in the case of the ongoing SARS-CoV-2 pandemic. We discovered that a lysine- and arginine-specific supramolecular ligand (CLR01) destroys enveloped viruses, including HIV, Ebola, and Zika virus, and remodels amyloid fibrils in semen that promote viral infection. Yet, it is unknown how CLR01 exerts these two distinct therapeutic activities. Here, we delineate a novel mechanism of antiviral activity by studying the activity of tweezer variants: the "phosphate tweezer" CLR01, a "carboxylate tweezer" CLR05, and a "phosphate clip" PC. Lysine complexation inside the tweezer cavity is needed to antagonize amyloidogenesis and is only achieved by CLR01. Importantly, CLR01 and CLR05 but not PC form closed inclusion complexes with lipid head groups of viral membranes, thereby altering lipid orientation and increasing surface tension. This process disrupts viral envelopes and diminishes infectivity but leaves cellular membranes intact. Consequently, CLR01 and CLR05 display broad antiviral activity against all enveloped viruses tested, including herpesviruses, Measles virus, influenza, and SARS-CoV-2. Based on our mechanistic insights, we potentiated the antiviral, membrane-disrupting activity of CLR01 by introducing aliphatic ester arms into each phosphate group to act as lipid anchors that promote membrane targeting. The most potent ester modifications harbored unbranched C4 units, which engendered tweezers that were approximately one order of magnitude more effective than CLR01 and nontoxic. Thus, we establish the mechanistic basis of viral envelope disruption by specific tweezers and establish a new class of potential broad-spectrum antivirals with enhanced activity.


Subject(s)
Antiviral Agents/chemistry , Antiviral Agents/pharmacology , Bridged-Ring Compounds/pharmacology , Organophosphates/pharmacology , Viral Envelope Proteins/drug effects , Acid Phosphatase/chemistry , Acid Phosphatase/metabolism , Amyloid/antagonists & inhibitors , Anti-HIV Agents/chemistry , Anti-HIV Agents/pharmacology , Arginine/chemistry , Betacoronavirus/drug effects , Bridged-Ring Compounds/chemistry , Cell Membrane/chemistry , Cell Membrane/drug effects , Cell Membrane/virology , HIV Infections/drug therapy , HIV-1/drug effects , Humans , Lipids/chemistry , Lysine/chemistry , Magnetic Resonance Spectroscopy , Organophosphates/chemistry , SARS-CoV-2 , Seminal Vesicle Secretory Proteins/chemistry , Seminal Vesicle Secretory Proteins/metabolism , Structure-Activity Relationship , Viral Envelope Proteins/metabolism , Zika Virus/drug effects
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