Biology subjects

Kratochvil, J.

Publications and source records attributed to Kratochvil, J..

3 recordsLinked to original sources

bioRxiv2026

Allosteric remodelling of the Ebola virus glycoprotein underlies differences in entry mechanisms across species

During Ebolavirus transit through the endo-lysosomal pathway, the glycoprotein GP undergoes a series of conformational rearrangements upon cathepsin cleavage and NPC1 receptor binding, culminating in host-virus membrane fusion. While these rearrangements underpin viral entry, their molecular mechanisms remain poorly understood. Here, we combine hydrogen/deuterium-exchange mass spectrometry and mass photometry to resolve structural dynamic and energetic transitions of GP of two major species, Zaire (EBOV) and Sudan (SUDV). We describe the allosteric axes that govern reorganization of the cleavage sites, opening of the receptor binding cavity and priming for fusion upon NPC1 engagement. We show that GP cathepsin cleavage and receptor binding exhibit different mechanisms and kinetics across species, and are allosterically coupled in a species-specific manner. We reveal that fusion priming is optimized via distinct routes in EBOV and SUDV GP. These data suggest that GP structural dynamics and allosteric remodelling underlie differences in entry mechanisms across Ebolavirus species.

biochemistry↗

bioRxiv2026

The schizophrenia associated protein DISC1 is a multivalent tetrameric hub of conserved ancient fold

DISC1 is a pleiotropic protein with essential roles in neuronal proliferation and migration, intracellular signalling and cargo transport. It associates with a diverse array of partner molecules in these contexts. Mutations at the DISC1 locus are strongly associated with a spectrum of mental illnesses such as schizophrenia and depression. Despite its clinical relevance, the molecular architecture and function of DISC1 have remained largely elusive. We present a cryo-EM structure of the entire conserved core region of DISC1. The structure reveals an intricate homotetrameric assembly that harbours conserved bacteria-derived UVR domains. Four of these domains, one from each monomer, mediate extensive contacts forming two asymmetric dimer units. The dimers in turn interface with each other at two distinct coiled coil domains to achieve a two-fold symmetric tetramer. Mutational analysis shows that this tetrameric architecture enables DISC1 to simultaneously bind multiple copies of NDE1 client protein. Importantly, tetramerization and partner binding are structurally independent functions of DISC1. Altogether, our study provides a compelling molecular model of an ancient bacteria protein fold participating in the assembly of a multivalent mammalian scaffold hub that can coordinate multiple partner molecules.

neuroscience↗

bioRxiv2024

Best practice mass photometry: A guide to optimal single molecule mass measurement

Mass photometry (MP) has emerged as a powerful approach to study biomolecular structure, dynamics and interactions. The capabilities of the method ultimately hinge on the ability to accurately measure the tiny optical contrast generated by individual molecules landing at a glass-water interface, which enables mass-resolved quantification of biomolecular mixtures. Ideally, this capability is only limited by shot noise inherent to photon detection, but in practice depends on additional parameters and details of the assay. Here, we focus on the key parameters affecting MP performance, and present simple steps that can be taken to achieve optimal MP performance in terms of mass resolution, quantitative detection limit and analyte concentration range without compromising the ease and simplicity of the technique.

biophysics↗