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Lecoq, L.

Publications and source records attributed to Lecoq, L..

2 recordsLinked to original sources

Biomolecular solid-state NMR spectroscopy at highest field: the gain in resolution at 1200 MHz

Progress in NMR in general and in biomolecular applications in particular is driven by increasing magnetic-field strengths leading to improved resolution and sensitivity of the NMR spectra. Recently, persistent superconducting magnets at a magnetic field strength (magnetic induction) of 28.2 T corresponding to 1200 MHz proton resonance frequency became commercially available. We present here a collection of high-field NMR spectra of a variety of proteins, including molecular machines, membrane proteins and viral capsids and others. We show this large panel in order to provide an overview over a range of representative systems under study, rather than a single best performing model system. We discuss both carbon-13 and proton-detected experiments, and show that in 13C spectra substantially higher numbers of peaks can be resolved compared to 850 MHz while for 1H spectra the most impressive increase in resolution is observed for aliphatic side-chain resonances.

biophysics

SARS-CoV-2 ORF7b: is a bat virus protein homologue a major cause of COVID-19 symptoms?

ORF7b is an accessory protein of SARS-CoV-2, the virus behind the COVID-19 pandemic. Using cell-free synthesized ORF7b, we experimentally show that ORF7b assembles into stable multimers. The ORF7b sequence shows a transmembrane segment, which multimerizes through a leucine zipper. We hypothesize that ORF7b has the potential to interfere with important cellular processes that involve leucine-zipper formation, and present two particularly striking examples. First, leucine zippers are central in heart rhythm regulation through multimerization of phospholamban in cardiomyocytes. Second, epithelial cell-cell adhesion relies on E-cadherins, which dimerize using a transmembrane leucine zipper. Most common symptoms of SARS-CoV-2 infection, including heart arrythmias, odor loss, impaired oxygen uptake and intestinal problems, up to multiorgan failure, can be rationalized by a possible interference of ORF7b with the functions of these proteins. We ask whether this is pure coincidence, or whether our observations point to disruption by ORF7b of vital processes in COVID-19.

biochemistry