SARS-CoV-2 proteins bind heme and hemoglobin [article]

Salvatore Giovanni De-Simone, Guilherme Curty Lechuga, Franklin Souza-Silva, Carolina de Queiroz Sacramento, Monique Ramos de Oliveira Trugilho, Richard Hemmi Valente, Paloma Napoleão-Pêgo, Suelen da SIlva Gomes Dias, Natalia Fintelman-Rodrigues, Jairo Ramos Temerozzo, Nicolas Carels, Carlos Roberto Alves (+3 others)
2021 bioRxiv   pre-print
The coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome virus 2 (SARS-CoV-2), has led to a global crisis that included collapsing healthcare systems and shut-down communities, producing considerable economic burden. Despite the number of effective vaccines quickly implemented, the emergence of new variants is a primary concern. The scientific community undertook a rapid response to better study this new virus. However, critical questions about viral
more » ... protein interactions and mechanisms of its physiopathology are still unclear. Although severe COVID-19 was associated with hematological dysfunctions, scarce experimental data were produced about iron dysmetabolism and the viral proteins' possible interaction with hemoglobin (Hb) chains. This work demonstrates the binding of SARS-CoV-2 proteins to hemin and Hb using a multimethodological approach. In silico analysis indicated binding motifs between a cavity in the viral nucleoprotein and hemoglobin's porphyrin coordination region. Different hemin binding capacities of mock and SARS-CoV-2-infected culture extracts were noticed using gel electrophoresis and TMB staining. Hemin-binding proteins were isolated from SARS-CoV-2-infected cells by affinity chromatography and identified by shotgun proteomics, indicating that structural (nucleoprotein, spike, and membrane protein) and non-structural (Nsp3 and Nsp7) viral proteins interact with hemin. In vitro analyses of virus adsorption to host cells and viral replication studies in Vero cells demonstrated inhibitory activities - at different levels - by hemin, protoporphyrin IX (PpIX) Hb. Strikingly, free Hb at 1mM suppressed viral replication (99 %), and its interaction with SARS-CoV-2 was localized to the RBD region of the Spike protein. The findings showed clear evidence of new avenues to disrupt viral replication and understand virus physiopathology that warrants further investigation.
doi:10.1101/2021.04.16.440124 fatcat:egtl3zx23zgyzj53gztffcirqy