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Cell lines for vaccine production
Published in Amine Kamen, Laura Cervera, Bioprocessing of Viral Vaccines, 2023
Isabelle Knott, Jean-Philippe Matheise, Isabelle Ernest, Jean-Pol Cassart
Protein-mass spectrometry by MALDI TOF is also considered as an attractive alternative for the detection of viruses, but its application is very limited by the sensitivity required and by the complexity of the samples typically used. Coupled separation techniques like 2-D gel electrophoresis, in addition to peptide analysis by LC-MS/MS, are powerful methods used for detection of unknown viruses in complex samples.
Rhenium complexes as antiviral agents for COVID-19
Published in Journal of Coordination Chemistry, 2022
The binding of the metal-based compound towards Mpro was investigated by electrospray ionization protein mass spectrometry (ESI-MS). While the protein itself had a molecular mass of 33797 Da, upon incubation with 22 a new species emerged at 34225 Da, corresponding to a single metal complex bound to the enzyme [21]. To identify the amino acid residue the metal complex was interacting with, Mpro was pre-incubated with the organic covalent binder GC376, which has previously been described to bind to the catalytical Cys145 residue [22], followed by incubation with 22. Upon incubation with 22, no additional adduct formation was observed, suggesting that the metal complex targets the same residue as GC376. Based on the high thiophilicity of the metal complexes and the high concentrations of free cysteine and glutathione inside of human cells, the activity of 22 was monitored in the presence of these biological thiols. HPLC studies demonstrated that the metal complexes were able to generate coordinative covalent bonds with thiols; however, this binding is reversible in the presence of other thiols. In agreement with the HPLC data, the inhibitory effect of 34 was only slightly decreased upon the addition of glutathione [21]. Notably, the therapeutic effect of other metal-based drugs such as cisplatin is also reduced in the presence of glutathione [23]. The selectivity of 34 towards other human proteases including the aspartate protease beta-secretase 1, serine protease dipeptidyl peptidase-4, and cysteine protease cathepsin B was studied. Complex 34 was found with no or only very low inhibitory activity, demonstrating selectivity for Mpro [21]. A recent screening of metal complexes showed that related Re(I) tricarbonyl complexes were inactive or poorly active towards the SARS-CoV-2 papain-like protease or the interaction of the spike protein with the angiotensin-converting enzyme II receptor [13]. Despite their promising enzymatic inhibition towards Mpro, 2,2′-bipyridine coordinated aqua Re(I) tricarbonyl complexes have been reported to be cytotoxic [24], which may limit their use as antiviral agents. Therefore, there is a need for further optimization of these Re(I) tricarbonyl complexes to generate a compound with high affinity and selectivity for Mpro without undesired cytotoxic side effects.