Daniel Luque is a biochemist and group leader of the Electron and Confocal Microscopy Unit of the Instituto de Salud Carlos III (ISCIII), in Madrid (Spain). He graduated in Biochemist from Autónoma University in Madrid (UAM, Madrid), and then completed a PhD in Molecular Biology from the UAM. He worked as a postdoctoral researcher at the National Center for Biotechnology of the National Research Spanish Council (CSIC) characterizing different viral systems by cryo-EM and image processing. Additionally, he has worked in the biotechnology company Kapsid Link S.L. developing nanotransporters for drug delivery and gene therapy based on viral capsids. In 2009, he joined the National Center of Microbiology (ISCIII) initiating a new research line focused on the structural characterization of the macromolecular complexes associated with the morphogenesis of Rotavirus and other viral pathogens by means of the combination of three-dimensional cryo-EM with other biophysical and molecular biology techniques.
Intro for presentation
The study of viral capsids by atomic force microscopy (AFM) has been shown as a powerful technique to unravel physicochemical properties, such as mechanics and electrostatics, at single particle level. We have characterized the stiffness, breaking force, critical strain and mechanical fatigue of individual Triple, Double and Single layered particles of Rotavirus in order to probe to the mechanics of the three different layers that built the Rotavirus particle and unveil the interplay among proteins structure, function and biophysical properties. Our data shows that the outermost shell, formed by VP7 subunits, has the needed resistance to support the stringent conditions of extracellular media. Indeed, fatigue experiments revealed a strong interaction between the external and the middle layers. The suppression of this interaction by the removal of Ca ions induces the disassembly of the external layer turning the virus into the transcriptionally active double-layered particle. The intermediate layer presents weak hydrophobic interactions with the inner layer that overcome the symmetry mismatch between them and favor the conformational dynamics of transcription. Our work shows how the biophysical properties and interactions of the three particles shells are finely tuned to produce an infective Rotavirus virion.