tetano
Editor, Senior Moderator
Spectrochim Acta A Mol Biomol Spectrosc
. 2024 Jul 6:322:124772.
doi: 10.1016/j.saa.2024.124772. Online ahead of print. Dimeric and monomeric conformation of SARS-CoV-2 main protease: New technical approaches based on IR radiation
Federica Piccirilli[SUP] 1 [/SUP], Hendrik Vondracek[SUP] 2 [/SUP], Lucia Silvestrini[SUP] 3 [/SUP], Pietro Parisse[SUP] 4 [/SUP], Francesco Spinozzi[SUP] 3 [/SUP], Lisa Vaccari[SUP] 2 [/SUP], Andrea Toma[SUP] 5 [/SUP], Vincenzo Aglieri[SUP] 5 [/SUP], Loredana Casalis[SUP] 2 [/SUP], Antonio Palumbo Piccionello[SUP] 6 [/SUP], Paolo Mariani[SUP] 3 [/SUP], Giovanni Birarda[SUP] 7 [/SUP], Maria Grazia Ortore[SUP] 8 [/SUP]
Affiliations
The main proteases M[SUP]pro[/SUP] are a group of highly conserved cysteine hydrolases in β-coronaviruses. They have been demonstrated to play an unavoidable role in viral replication, and consequently they have been suggested as key targets for treating coronavirus-caused infectious diseases, mainly from the COVID-19 epidemic. Since the most functional form for M[SUP]pro[/SUP] enzymatic activity is associated to its homodimer, compounds inhibiting dimerization should also inhibit catalytic activity. We show how PIR-SEIRA (Plasmonic Internal Reflection-Surface Enhanced InfraRed Absorption) spectroscopy can be a noteworthy technique to study proteins subtle structural variations associated to inhibitor binding. Nanoantennas arrays can selectively confine and enhance electromagnetic field via localized plasmonic resonances, thus promoting ultrasensitive detection of biomolecules in close proximity of nanoantenna arrays and enabling the effective investigation of protein monolayers. By adopting this approach, reflection measurements conducted under back illumination of nanoantennas allow to probe anchored protein monolayers, with minimum contribution of environmental buffer molecules. PIR-SEIRA spectroscopy on M[SUP]pro[/SUP] was carried out by ad hoc designed devices, resonating in the spectral region of Amide I and Amide II bands. We evaluated here the structure of anchored monomers and dimers in different buffered environment and in presence of a newly designed M[SUP]pro[/SUP] inhibitor. Experimental results show that dimerization is not associated to relevant backbone rearrangements of the protein at secondary structure level, and even if the compound inhibits the dimerization, it is not effective at breaking preformed dimers.
Keywords: Equilibria; IR; Protease; SARS-COV2.
. 2024 Jul 6:322:124772.
doi: 10.1016/j.saa.2024.124772. Online ahead of print. Dimeric and monomeric conformation of SARS-CoV-2 main protease: New technical approaches based on IR radiation
Federica Piccirilli[SUP] 1 [/SUP], Hendrik Vondracek[SUP] 2 [/SUP], Lucia Silvestrini[SUP] 3 [/SUP], Pietro Parisse[SUP] 4 [/SUP], Francesco Spinozzi[SUP] 3 [/SUP], Lisa Vaccari[SUP] 2 [/SUP], Andrea Toma[SUP] 5 [/SUP], Vincenzo Aglieri[SUP] 5 [/SUP], Loredana Casalis[SUP] 2 [/SUP], Antonio Palumbo Piccionello[SUP] 6 [/SUP], Paolo Mariani[SUP] 3 [/SUP], Giovanni Birarda[SUP] 7 [/SUP], Maria Grazia Ortore[SUP] 8 [/SUP]
Affiliations
- PMID: 39003826
- DOI: 10.1016/j.saa.2024.124772
The main proteases M[SUP]pro[/SUP] are a group of highly conserved cysteine hydrolases in β-coronaviruses. They have been demonstrated to play an unavoidable role in viral replication, and consequently they have been suggested as key targets for treating coronavirus-caused infectious diseases, mainly from the COVID-19 epidemic. Since the most functional form for M[SUP]pro[/SUP] enzymatic activity is associated to its homodimer, compounds inhibiting dimerization should also inhibit catalytic activity. We show how PIR-SEIRA (Plasmonic Internal Reflection-Surface Enhanced InfraRed Absorption) spectroscopy can be a noteworthy technique to study proteins subtle structural variations associated to inhibitor binding. Nanoantennas arrays can selectively confine and enhance electromagnetic field via localized plasmonic resonances, thus promoting ultrasensitive detection of biomolecules in close proximity of nanoantenna arrays and enabling the effective investigation of protein monolayers. By adopting this approach, reflection measurements conducted under back illumination of nanoantennas allow to probe anchored protein monolayers, with minimum contribution of environmental buffer molecules. PIR-SEIRA spectroscopy on M[SUP]pro[/SUP] was carried out by ad hoc designed devices, resonating in the spectral region of Amide I and Amide II bands. We evaluated here the structure of anchored monomers and dimers in different buffered environment and in presence of a newly designed M[SUP]pro[/SUP] inhibitor. Experimental results show that dimerization is not associated to relevant backbone rearrangements of the protein at secondary structure level, and even if the compound inhibits the dimerization, it is not effective at breaking preformed dimers.
Keywords: Equilibria; IR; Protease; SARS-COV2.