A study by the University of Southampton has revealed that ultraviolet laser light effectively deactivates SARS-CoV-2 by damaging its genetic material and protein spikes. This discovery, enhancing the understanding of light-based virus deactivation, paves the way for novel disinfection methods in environments where traditional approaches are not feasible. Credit: University of Southampton
New research has revealed how light can be used to destroy infectious coronavirus particles that contaminate surfaces. Scientists are interested in how environments, such as surgeries, can be thoroughly disinfected from viruses such as SARS-CoV-2Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the official name of the virus strain that causes coronavirus disease (COVID-19). Previous to this name being adopted, it was commonly referred to as the 2019 novel coronavirus (2019-nCoV), the Wuhan coronavirus, or the Wuhan virus.” data-gt-translate-attributes=”[{“attribute”:”data-cmtooltip”, “format”:”html”}]” tabindex=”0″ role=”link”>SARS-CoV-2 that caused the COVID-19First identified in 2019 in Wuhan, China, COVID-19, or Coronavirus disease 2019, (which was originally called "2019 novel coronavirus" or 2019-nCoV) is an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). It has spread globally, resulting in the 2019–22 coronavirus pandemic.” data-gt-translate-attributes=”[{“attribute”:”data-cmtooltip”, “format”:”html”}]” tabindex=”0″ role=”link”>COVID-19 pandemic.
SARS-CoV-2 viral particles are composed of a core of nucleic acidAny substance that when dissolved in water, gives a pH less than 7.0, or donates a hydrogen ion.” data-gt-translate-attributes=”[{“attribute”:”data-cmtooltip”, “format”:”html”}]” tabindex=”0″ role=”link”>acid chains that contain the genetic information of the virusA virus is a tiny infectious agent that is not considered a living organism. It consists of genetic material, either DNA or RNA, that is surrounded by a protein coat called a capsid. Some viruses also have an outer envelope made up of lipids that surrounds the capsid. Viruses can infect a wide range of organisms, including humans, animals, plants, and even bacteria. They rely on host cells to replicate and multiply, hijacking the cell's machinery to make copies of themselves. This process can cause damage to the host cell and lead to various diseases, ranging from mild to severe. Common viral infections include the flu, colds, HIV, and COVID-19. Vaccines and antiviral medications can help prevent and treat viral infections.” data-gt-translate-attributes=”[{“attribute”:”data-cmtooltip”, “format”:”html”}]” tabindex=”0″ role=”link”>virus, surrounded by a lipid membrane with proteinous spikes sticking out. Each component is necessary for infection.
Researchers from the University of Southampton investigated how ultraviolet laser light destroys the virus by impacting each of these critical components. By using a specialized ultraviolet laser at two different wavelengths the scientists were able to determine how each viral component degraded under the bright light. They found the genomic material was highly sensitive to degradation and protein spikes lost their ability to bind to human cells.
The Role of UVC Light in Viral Deactivation
UV light includes UVA, UVB, and UVC light. Very little UVC light at frequencies below 280nm reaches the earth’s surface from the sun. It is this lesser-studied UVC light that the team in Southampton used for their study due to its disinfectant properties. UVC light is strongly absorbed by different viral components, including the genetic material (~260nm) and the proteinous spikes (~230nm), allowing the team to select laser frequencies of 266nm and 227nm for the project.
The University of Southampton scientists, led by Professor Sumeet Mahajan, worked closely with scientists from the laser manufacturer, called M Squared Lasers, and the resulting co-authored study has been published in a journal of the American Chemical Society called ACS Photonics. The team found that 266nm light caused RNARibonucleic acid (RNA) is a polymeric molecule similar to DNA that is essential in various biological roles in coding, decoding, regulation and expression of genes. Both are nucleic acids, but unlike DNA, RNA is single-stranded. An RNA strand has a backbone made of alternating sugar (ribose) and phosphate groups. Attached to each sugar is one of four bases—adenine (A), uracil (U), cytosine (C), or guanine (G). Different types of RNA exist in the cell: messenger RNA (mRNA), ribosomal RNA (rRNA), and transfer RNA (tRNA).” data-gt-translate-attributes=”[{“attribute”:”data-cmtooltip”, “format”:”html”}]” tabindex=”0″ role=”link”>RNA damage at low powers, affecting the genetic information of the virus. 266nm light also damaged the structure of the SARS-CoV-2 spike protein, reducing its ability to bind to human cells by breaking down disulfide bonds and aromatic amino acids<div class="cell text-container large-6 small-order-0 large-order-1">
<div class="text-wrapper"><br />Amino acids are a set of organic compounds used to build proteins. There are about 500 naturally occurring known amino acids, though only 20 appear in the genetic code. Proteins consist of one or more chains of amino acids called polypeptides. The sequence of the amino acid chain causes the polypeptide to fold into a shape that is biologically active. The amino acid sequences of proteins are encoded in the genes. Nine proteinogenic amino acids are called "essential" for humans because they cannot be produced from other compounds by the human body and so must be taken in as food.<br /></div>
</div>” data-gt-translate-attributes=”[{“attribute”:”data-cmtooltip”, “format”:”html”}]” tabindex=”0″ role=”link”>amino acids.
The 227nm light was less effective at inducing RNA damage, but more effective at damaging proteins through oxidation (a chemical reaction involving oxygen) which unfolds the protein’s structure.
Implications of the Research
Importantly, SARS-CoV-2 has among the largest genomes for RNA viruses. This makes it especially sensitive to genomic damage.
Professor Mahajan said: “Light deactivation of airborne viruses offers a versatile tool for disinfection of our public spaces and sensitive equipment that may otherwise prove difficult to decontaminate with conventional methods. Now we understand the differential sensitivity of molecular components in viruses to light deactivation this opens up the possibility of a finely tuned disinfection technology.”
Light-based deactivation has received a lot of attention because of the wide range of applications where conventional liquid-based deactivation methods aren’t suitable. Now the mechanism of deactivation is better understood this is an important step in rolling out the technology.
Reference: “Mechanisms of SARS-CoV-2 Inactivation Using UVC Laser Radiation” by George Devitt, Peter B. Johnson, Niall Hanrahan, Simon I. R. Lane, Magdalena C. Vidale, Bhavwanti Sheth, Joel D. Allen, Maria V. Humbert, Cosma M. Spalluto, Rodolphe C. Hervé, Karl Staples, Jonathan J. West, Robert Forster, Nullin Divecha, Christopher J. McCormick, Max Crispin, Nils Hempler, Graeme P. A. Malcolm and Sumeet Mahajan, 26 December 2023, ACS Photonics.
DOI: 10.1021/acsphotonics.3c00828
Source: SciTechDaily
