Creatine kinase B deficient neurons exhibit an increased fraction of motile mitochondria

Background  

Neurons require an elaborate system of intracellular transport to distribute cargo throughout axonal and dendritic projections. Active anterograde and retrograde transport of mitochondria serves in local energy distribution, but at the same time also requires input of ATP. Here we studied whether brain-type creatine kinase (CK-B), a key enzyme for high-energy phosphoryl transfer between ATP and CrP in brain, has an intermediary role in the reciprocal coordination between mitochondrial motility and energy distribution. Therefore, we analysed the impact of brain-type creatine kinase (CK-B) deficiency on transport activity and velocity of mitochondria in primary murine neurons and made a comparison to the fate of amyloid precursor protein (APP) cargo in these cells, using live cell imaging.     

Deriving the magnitude of niobium off-center displacement in ferroelectric niobates from infrared spectroscopy

A KSr₂Nb₅O₁₅ nanopowder was synthesized by a chemical route based on a modified polyol method. The nanopowder exhibits the space group P4bm (ferroelectric) ascribed to the displacement of Nb from the central position of an [NbO₆] octahedron, parallel to the c-axis (polarization axis). The magnitude of the niobium off-center, ∆z, was determined by X-ray diffraction and mid-infrared spectroscopy (FTIR). Analysis of the infrared spectrum carried out using curve fitting based on Gaussian functions has revealed a very strong vibration at 413 cm^–1, ascribed to a bond of the Nb off-center with apical oxygen. A classical molecular theory was applied to derive the force constant of this bond from the vibrational frequency. Using the calculus of energies for the wavelength and the harmonic oscillator, we alternatively derived the ∆z parameter.     

Partial and Gradual Hydrolysis of 2,2′-Biimidazoline upon Coordination to Metal Ions,yielding New Chelating Ligands - Synthesis,Characterization and X-ray Structure of two Examples with Cobalt(III) and Copper(II)

The synthesis, a full structural characterization of two transition-metal compounds obtained by in-situ hydrolysis and partly hydrolysis of the ligand 2, 2′-biimidazoline (abbreviated as biz) is reported. When the biz ligand is completely hydrolysed the compound, N, N′-bis(2-aminoethyl)oxamide (abbreviated as H₂oxen) is obtained, while the partial hydrolysis results in the ligand N-(2-aminoethyl)imidazoline-2-carboxamide (abbreviated as Hoxim). The Co^III ion in the mononuclear Co^III compound, [Co(biz)(oxim)(NCS)](ClO₄)(C₂H₅OH)_1/6(H₂O)_1/6 ( 1 ), has an octahedral coordination consisting of 6 nitrogen atoms with a distance varying from 1.889(6) to 1.950(5) Å. Two nitrogen atoms originating from a biz molecule, 3 nitrogen atoms are from the oxim ligand and one nitrogen is from the thiocyanate anion. Each Cu^II ion in the dinuclear Cu^II compound, [Cu₂(H₂oxen)(oxim)₂(C₂H₅OH)₂] (ClO₄)₂ ( 2 ), has a slightly distorted square-pyramidal structure of which the basal plain consists of3 nitrogen atoms of the oxim ligand and one nitrogen atom of the H₂oxen ligand, which is used as a “spacer” connecting the second Cu^II atom, with Cu-N distances which vary from 1.944(2) to 2.037(2) Å. The apical position is formed by the oxygen atom of a semi-coordinating ethanol molecule with a Cu-O distance of 2.446(2) Å. The compounds are characterized by elemental analysis, ligand field, infrared and, for the Cu^II ion, also by EPR spectroscopy.