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bioRxiv2021

In vitro determination of inhibitory effects by humic substances complexing Zn and Se on SARS-CoV-2 virus replication

Humic substances are well known human nutritional supplement materials and play important performance-enhancing roles as animal feed additives, too. For decades, ingredients of humic substances have also been proven to carry potent antiviral effects against different viruses. Here, the antiviral activity of a humic substance containing ascorbic acid, Se- and Zn2+ ions intended as a nutritional supplement material was investigated against SARS-CoV-2 virus B1.1.7 Variant of Concern ("Alpha Variant") in a VeroE6 cell line. Results show that this combination has a significant in vitro antiviral effect at a very low concentration range of its intended active ingredients. Even picomolar concentration ranges of humic substances, vitamin C and Zn/Se ions in the given composition were enough to achieve fifty percent viral replication inhibition in the applied SARS-CoV-2 virus inhibition test.

microbiology↗

bioRxiv2020

Topography, spike dynamics and nanomechanics of individual native SARS-CoV-2 virions

SARS-CoV-2, the virus responsible for the current COVID-19 pandemic, displays a corona-shaped layer of spikes which play fundamental role in the infection process. Recent structural data suggest that the spikes possess orientational freedom and the ribonucleoproteins segregate into basketlike structures. How these structural features regulate the dynamic and mechanical behavior of the native virion, however, remain unknown. By imaging and mechanically manipulating individual, native SARS-CoV-2 virions with atomic force microscopy, here we show that their surface displays a dynamic brush owing to the flexibility and rapid motion of the spikes. The virions are highly compliant and able to recover from drastic mechanical perturbations. Their global structure is remarkably temperature resistant, but the virion surface becomes progressively denuded of spikes upon thermal exposure. Thus, both the infectivity and thermal sensitivity of SARS-CoV-2 rely on the dynamics and the mechanics of the virus. One sentence summaryThe native coronavirus 2 displays a dynamic surface layer of spikes, a large mechanical compliance and unique self-healing capacity.

biophysics↗