ABSTRACT
The organism-wide effects of viral infection SARS-CoV-2 are well studied, but little is known about the dynamics of how the infection spreads in time among or within cells due to the scarcity of suitable high-resolution experimental systems. Two-photon (2P) imaging combined with a proper subcellular staining technique has been an effective tool for studying mechanisms at such resolutions and organelle levels. Herein, we report the development of a novel calcium sensor molecule along with a 2P-technique for identifying imaging patterns associated with cellular correlates of infection damage within the cells. The method works as a cell viability assay and also provides valuable information on how the calcium level and intracellular distribution are perturbed by the virus. Moreover, it allows the quantitative analysis of infection dynamics. This novel approach facilitates the study of the infection progression and the quantification of the effects caused by viral variants and viral load.
ABSTRACT
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.
ABSTRACT
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.
ABSTRACT
EPR spectroscopy is employed to demonstrate chemical production of formally Fe(i) and Fe(0) states of phthalocyanines in water at room temperature, and physiologically-relevant pH.
