Examine reveals hyperlink between selenium and COVID-19 severity

Chemists from the College of North Carolina at Greensboro launched a examine within the journal Antioxidants revealing a brand new foundation for the hyperlink between dietary selenium and COVID-19 severity. Constructing on a earlier examine that recognized a set of six host proteins probably focused by SARS-CoV-2, their examine confirmed cleavage of three beforehand predicted protein goal websites from selenoproteins, which have antioxidant and antiviral defensive roles.

As well as, they found that the viral protease targets and probably inactivates the rate-limiting enzyme in glutathione synthesis, glutamate-cysteine ligase catalytic subunit (GCLC). Their findings point out that COVID destroys the antioxidant exercise of a key human selenoprotein and divulges a foundation for decreased glutathione ranges which can be seen in COVID-19 sufferers, which weakens immunity and permits the virus to copy extra effectively.

“That is the primary time {that a} examine has proven a virus to have an lively technique to destroy human selenium-containing proteins,” stated Ethan W. Taylor, professor of biomedical chemistry at UNCG and one of many authors of the examine. “Selenium biochemistry could also be a key in understanding the best way to strengthen the immune system in opposition to COVID.”

The authors of the examine–Ignacio A. Gallardo, Daniel A. Todd, Stella T. Lima, Jonathan R. Checkan, Norman H. Chu, and Taylor, all researchers within the Division of Chemistry and Biochemistry–constructed on earlier analysis that established the affiliation between dietary selenium ranges and the scientific final result of viral infections.

Following up on a 2020 paper from the Taylor group that recognized six host proteins that comprise potential SARS-CoV-2 essential protease (M^professional) cleavage websites, they demonstrated experimentally that M^professional can cleave 4 of the six predicted goal websites, together with these from three selenoproteins: thioredoxin reductase 1 (TXNRD1), selenoprotein F and selenoprotein P, in addition to the rate-limiting enzyme in glutathione synthesis, glutamate-cysteine ligase catalytic subunit (GCLC).

The cloned full size TXNRD1 protein was cleaved by SARS-CoV-2 M^professional in a fashion that destroyed its antioxidant exercise, by slicing off its C-terminal redox heart.

“The category of proteins focused by the virus for proteolysis have antioxidant and antiviral defensive roles, as they will disrupt the construction of viral proteins through disulfide bond discount,” stated Taylor. “Thus, viral infectivity may very well be enhanced by knockdown of a number of of those proteins.”

Proteolytic knockdown of each TXNRD1 and GCLC can also be in line with a viral technique to inhibit DNA synthesis, conserving the pool of ribonucleotides for elevated RNA synthesis and virus manufacturing.

These analysis findings recommend a necessity for additional investigation of the scientific potential not solely of selenium supplementation, but additionally of varied dietary sulfur compounds which can be precursors of glutathione. These might embrace the well-known complement N-acetyl cysteine (NAC), the mix of NAC plus glycine, or gamma-glutamyl cysteine (GGC, the product of the GCLC enzyme that the virus is making an attempt to destroy).

Alternatively, the glutathione mimic alpha lipoic acid (ALA) can substitute in lots of the roles of glutathione itself. Additional investigation might result in new complementary symptomatic remedies for COVID sufferers.