We present an approach for constructing a realistic structure model of inhomogeneous amorphous materials by combining angstrom-beam electron diffraction, synchrotron X-ray scattering, and simulation techniques. Local structure information obtainable by angstrom-beam electron diffraction is effective to choose a probable model from some possible models that satisfy a structure factor of X-ray scattering. We applied this approach to amorphous SiO and successfully constructed a realistic model including nanoscale Si and SiO2-like regions together with abundant interfacial Si suboxides.
Iron is an essential element for almost all living organism as it serves as a catalytic center for redox and metabolic reactions in many enzymes. Bacterial pathogens have evolved the efficient systems for the heme acquisition to survive in the host tissues and body fluids, because the heme is a rich source of iron. Pathogens grab the heme from the host hemoproteins and import it into cytoplasm by using many proteins including hemophore and ATP hydrolysis-driven transporter. In this review, recent discoveries in the molecular mechanism of the heme acquisition, membrane transport, degradation and sensing of the heme, with particular emphasis on the recognition of the heme and the dynamics of protein conformation from structural viewpoint.
Protein kinases transfer the γ-phosphate group of ATP to the hydroxyl group of substrate protein. 518 human kinases are classified into serine/threonine kinases and tyrosine kinases, and individually and/or synergistically transduce physiologic stimuli into cell to promote cell proliferation or apoptosis, etc. Kinases are identified as drug targets because dysfunction of kinases leads to severe diseases such as cancers. In this review, I describe structural biology on kinases and drug discovery for the severe diseases such as cancers due to kinase dysfunction.
Microgravity environment has been used to obtain high-quality crystals. Strong magnetic force produced by a superconducting magnet can cancel out the gravity force, enabling construction of quasi-microgravity environment on earth. We developed a protein crystallization system which is composed of a superconducting magnet for the magnetic force-based quasi-microgravity and an inverted periscope for in situ observation of crystal growth. Crystals grown in the system showed improved and homogeneous quality.