This paper presents new structural data about mitochondria using correlative light and electron microscopy (CLEM) and cryo-electron tomography. These state-of-the-art structural biology methods allow studying biological objects at nanometer scales under natural conditions. Non-invasiveness of these methods makes them comparable to observing animals in their natural environment on a safari.
View Article and Find Full Text PDFThe analysis of cryo-electron tomography images of human and rat mitochondria revealed that the mitochondrial matrix is at least as crowded as the cytosol. To mitigate the crowding effects, metabolite transport in the mitochondria primarily occurs through the intermembrane space, which is significantly less crowded. The scientific literature largely ignores how enzyme systems and metabolite transport are organized in the crowded environment of the mitochondrial matrix.
View Article and Find Full Text PDFA new platform has been developed to facilitate the production of biologically active proteins and peptides in Escherichia coli. The platform includes an N-terminal self-associating L KD peptide fused to the SUMO protein (small ubiquitin-like protein modifier) from the yeast Saccharomyces cerevisiae, which is known for its chaperone activity. The target proteins are fused at the C termini of the L KD-SUMO fusions, and the resulting three-component fusion proteins are synthesized and self-assembled in E.
View Article and Find Full Text PDFIn the present study, cryo-electron tomography was used to investigate the localization of 2-oxoacid dehydrogenase complexes (OADCs) in cardiac mitochondria and mitochondrial inner membrane samples. Two classes of ordered OADC inner cores with different symmetries were distinguished and their quaternary structures modeled. One class corresponds to pyruvate dehydrogenase complexes and the other to dehydrogenase complexes of α-ketoglutarate and branched-chain α-ketoacids.
View Article and Find Full Text PDFExtracellular vesicles (EV) derived from stem cells have become an effective complement to the use in cell therapy of stem cells themselves, which has led to an explosion of research into the mechanisms of vesicle formation and their action. There is evidence demonstrating the presence of mitochondrial components in EV, but a definitive conclusion about whether EV contains fully functional mitochondria has not yet been made. In this study, two EV fractions derived from mesenchymal stromal stem cells (MSC) and separated by their size were examined.
View Article and Find Full Text PDFProtein nanoparticles (NPs) can be used as vaccine platforms for target antigen presentation. To conduct a proof-of-concept study to demonstrate that an effective NP platform can be built based on a short self-assembling peptide (SAP) rather than a large self-assembling protein. SUMO-based protein fusions (SFs) containing an N-terminal SAP and a C-terminal antigen were designed, expressed in and purified.
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