Synthetic Heparan Sulfate Mimetic Pixatimod (PG545) Potently Inhibits SARS-CoV-2 By Disrupting The Spike-ACE2 interaction

Se, Guimond; Mycroft-West, Courtney J.; Gandhi, Neha S.; Ja, Tree; Le, Tao; Cm, Spalluto; Mv, Humbert; Kr, Buttigieg; Coombes, Naomi; Mj, Elmore; Nyström, Kristina; Said, Joanna; Yx, Setoh; Amarilla, AA; Modhiran, Naphak; Jd, Sng; Chhabra, Mohit; Young, Philip R.; Lima, Marco A. P.; Yates, Edwin A.; Karlsson, Richard; Rl, Miller; Chen, Yen-Hsi; Bagdonaite, Ieva; Yang, Zifeng; Stewart, James; Hammond, Edward; Dredge, Keith; Wilkinson, Toby; Watterson, Daniel; Aa, Khromykh; Suhrbier, Andreas; Mw, Carroll; Trybala, Edward; Bergström, Tomas; Ferro,; Ma, Skidmore; Turnbull, JE

doi:10.1101/2020.06.24.169334

Cited by 13 publications

(17 citation statements)

References 77 publications

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“…Note: N/A (not applicable). Type of heparin Assay format Efficacy Proposed usage Follow up trial (reference) References Comments UFH SARS-CoV-2 viral plaque forming assay 70% inhibitio;100 μg/mL Therapeutic N/A [ 16 ] Recommendation as first-line use “Pixatimod (PG545)” Plaque assay, percent inhibition from the cytopathic effect 32–51% inhibition; 100 μg/mL Prophylactic/therapeutic N/A [ 22 ] Emphasizes multi-modality if heparin; possibly as prophylactic and therapeutic UFH Pseudotyped Lentivirus entry inhibition 5.99 μg/L N/A N/A [ 32 ] UFH (formulation) plaque inhibition assay with Vero E6 cells 25–41 μg ml Treatment N/A [ 33 ] Hexa- and octasaccharides Surface plasma resonance (SPR) spike-heparin interaction inhibition 38 nM Therapeutic [ 34 ] [ 35 ] Oligosaccharide based inhibitors UFH (High mol weight fractions) Virus binding assay to Calu3, human lung cancer cell line <0.05 U/ml Therapeutic Nebulized heparin [ 36 ] [ 37 ] Long-chain heparin molecules are more effective than small ones` …”

Section: Resultsmentioning

confidence: 99%

“…Another study has shown that SARS-CoV-2 is dependent not only on ACE2 but also requires heparan sulfate proteoglycans [ 21 ]. The S protein has been shown to interact with both heparan sulfate receptors and heparin [ 21 , 22 ]. As such, studies have shown that heparin was able to abrogate virus infection to a similar extent as ACE2-specific antibodies [ 18 ].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Heparin: A simplistic repurposing to prevent SARS-CoV-2 transmission in light of its in-vitro nanomolar efficacy

Gupta

Maciorowski

Zak

et al. 2021

International Journal of Biological Macromolecules

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The world is currently facing a novel coronavirus (SARS-CoV-2) pandemic. The greatest threat that is disrupting the normal functioning of society is the exceptionally high species independent transmission. Drug repurposing is understood to be the best strategy to immediately deploy well-characterized agents against new pathogens. Several repurposable drugs are already in evaluation for determining suitability to treat COVID-19. One such promising compound includes heparin, which is widely used in reducing thrombotic events associated with COVID-19 induced pathology. As part of identifying target-specific antiviral compounds among FDA and world-approved libraries using high-throughput virtual screening (HTVS), we previously evaluated top hits for anti-SARS-CoV-2 activity. Here, we report results of highly efficacious viral entry blocking properties of heparin (IC 50 = 12.3 nM) in the complete virus assay, and further, propose ways to use it as a potential transmission blocker. Exploring further, our in-silico analysis indicated that the heparin interacts with post-translational glycoconjugates present on spike proteins. The patterns of accessible spike-glycoconjugates in open and closed states are completely contrasted by one another. Heparin-binding to the open conformation of spike structurally supports the state and may aid ACE2 binding as reported with cell surface-bound heparan sulfate. We also studied spike protein mutant variants' heparin interactions for possible resistance. Based on available data and optimal absorption properties by the skin, heparin could potentially be used to block SARS-CoV-2 transmission. Studies should be designed to exploit its nanomolar antiviral activity to formulate heparin as topical or inhalation-based formulations, particularly on exposed areas and sites of primary viremia e.g. ACE2 rich epithelia of the eye (conjunctiva/lids), nasal cavity, and mouth.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Heparin: A simplistic repurposing to prevent SARS-CoV-2 transmission in light of its in-vitro nanomolar efficacy

Gupta

Maciorowski

Zak

et al. 2021

International Journal of Biological Macromolecules

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“… 9 , 10 Several reports have indicated that heparin or related structures can inhibit the infection process of SARS-CoV-2 in different cell lines. 11 − 14 …”

Section: Introductionmentioning

confidence: 99%

Heparan Sulfate Proteoglycans as Attachment Factor for SARS-CoV-2

et al. 2021

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Severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2) is causing an unprecedented global pandemic demanding the urgent development of therapeutic strategies. Microarray binding experiments, using an extensive heparan sulfate (HS) oligosaccharide library, showed that the receptor binding domain (RBD) of the spike of SARS-CoV-2 can bind HS in a length- and sequence-dependent manner. A hexasaccharide composed of IdoA2S-GlcNS6S repeating units was identified as the minimal binding epitope. Surface plasmon resonance showed the SARS-CoV-2 spike protein binds with a much higher affinity to heparin ( K D = 55 nM) compared to the RBD ( K D = 1 μM) alone. It was also found that heparin does not interfere in angiotensin-converting enzyme 2 (ACE2) binding or proteolytic processing of the spike. However, exogenous administered heparin or a highly sulfated HS oligosaccharide inhibited RBD binding to cells. Furthermore, an enzymatic removal of HS proteoglycan from physiological relevant tissue resulted in a loss of RBD binding. The data support a model in which HS functions as the point of initial attachment allowing the virus to travel through the glycocalyx by low-affinity high-avidity interactions to reach the cell membrane, where it can engage with ACE2 for cell entry. Microarray binding experiments showed that ACE2 and HS can simultaneously engage with the RBD, and it is likely no dissociation between HS and RBD is required for binding to ACE2. The results highlight the potential of using HS oligosaccharides as a starting material for therapeutic agent development.

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“…Additionally, it has been demonstrated that binding of heparin or heparan sulfate can induce significant conformational changes in the spike protein structure and that the receptor binding domain of the spike subunit contains a heparan sulfate binding site [ 26 , 27 ]. Recently, evidence has demonstrated that HSPG is a cell surface proteoglycan co-receptor with the ACE2 protein for recognition of SARS-CoV-2 spike protein [ [28] , [29] , [30] ].…”

Section: Introductionmentioning

confidence: 99%