Experimental and in silico evaluations of the possible molecular interaction between airborne particulate matter and SARS-CoV-2

Alice Romeo; Roberto Pellegrini; Maurizio Gualtieri; Barbara Benassi; Massimo Santoro; Federico Iacovelli; Milena Stracquadanio; Mattia Falconi; Carmela Marino; Gabriele Zanini; Caterina Arcangeli

doi:10.1016/j.scitotenv.2023.165059

Experimental and in silico evaluations of the possible molecular interaction between airborne particulate matter and SARS-CoV-2

Sci Total Environ. 2023 Oct 15:895:165059. doi: 10.1016/j.scitotenv.2023.165059. Epub 2023 Jun 21.

Affiliations

¹ Department of Biology, University of Rome Tor Vergata, Via della Ricerca Scientifica 1, 00133 Rome, Italy.
² Department of Biology, University of Rome Tor Vergata, Via della Ricerca Scientifica 1, 00133 Rome, Italy; Division of Health Protection Technologies, Italian National Agency for New Technologies, Energy and Sustainable Development (ENEA), 00123 Rome, Italy.
³ Division of Models and Technologies for Risks Reduction, Italian National Agency for New Technologies, Energy and Sustainable Development (ENEA), 40129 Bologna, Italy; Department of Earth and Environmental Sciences, Piazza della Scienza 1, University of Milano-Bicocca, Milano.
⁴ Division of Health Protection Technologies, Italian National Agency for New Technologies, Energy and Sustainable Development (ENEA), 00123 Rome, Italy.
⁵ Division of Models and Technologies for Risks Reduction, Italian National Agency for New Technologies, Energy and Sustainable Development (ENEA), 40129 Bologna, Italy.
⁶ Division of Health Protection Technologies, Italian National Agency for New Technologies, Energy and Sustainable Development (ENEA), 00123 Rome, Italy. Electronic address: caterina.arcangeli@enea.it.

Abstract

During the early stage of the COVID-19 pandemic (winter 2020), the northern part of Italy has been significantly affected by viral infection compared to the rest of the country leading the scientific community to hypothesize that airborne particulate matter (PM) could act as a carrier for the SARS-CoV-2. To address this controversial issue, we first verified and demonstrated the presence of SARS-CoV-2 RNA genome on PM_2.5 samples, collected in the city of Bologna (Northern Italy) in winter 2021. Then, we employed classical molecular dynamics (MD) simulations to investigate the possible recognition mechanism(s) between a newly modelled PM_2.5 fragment and the SARS-CoV-2 Spike protein. The potential molecular interaction highlighted by MD simulations suggests that the glycans covering the upper Spike protein regions would mediate the direct contact with the PM_2.5 carbon core surface, while a cloud of organic and inorganic PM_2.5 components surround the glycoprotein with a network of non-bonded interactions resulting in up to 4769 total contacts. Moreover, a binding free energy of -207.2 ± 3.9 kcal/mol was calculated for the PM-Spike interface through the MM/GBSA method, and structural analyses also suggested that PM attachment does not alter the protein conformational dynamics. Although the association between the PM and SARS-CoV-2 appears plausible, this simulation does not assess whether these established interactions are sufficiently stable to carry the virus in the atmosphere, or whether the virion retains its infectiousness after the transport. While these key aspects should be verified by further experimental analyses, for the first time, this pioneering study gains insights into the molecular interactions between PM and SARS-CoV-2 Spike protein and will support further research aiming at clarifying the possible relationship between PM abundance and the airborne diffusion of viruses.

Keywords: COVID-19 pandemic; Classical molecular dynamics simulation; PM(2.5); SARS-CoV-2.

MeSH terms

COVID-19*
Humans
Molecular Dynamics Simulation
Pandemics
Particulate Matter / analysis
RNA, Viral
SARS-CoV-2*

Substances

spike protein, SARS-CoV-2
Particulate Matter
RNA, Viral