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A single crystal calorimetry of a heptacopper(II) complex of [Cu7(μ3-Cl)2(μ3-OH)6-( d-pen-disulfide)3] which has a double-cubane structure supported by d-penicillaminedisulfides has been performed at low-temperature region below 8 K. This compound is a metal complex which contains seven Cu(II)s in a cluster unit. These Cu(II)s are magnetically coupled each other by strong intra-complex interactions. The heat capacities under magnetic fields exhibit Schottky type anomalies explained by the Zeeman splitting of the doublet ground state of the complex. The g-value of the ground state is evaluated as 1.86 from the systematic analysis of the Schottky peak under magnetic fields. The first excited state of the cluster seems to be separated at least by several Kelvins, which is consistent with the theoretical calculations and magnetic susceptibility results. [ABSTRACT FROM AUTHOR]

A single crystal calorimetry of a heptacopper(II) complex of [Cu7(μ3-Cl)2(μ3-OH)6-( d-pen-disulfide)3] which has a double-cubane structure supported by d-penicillaminedisulfides has been performed at low-temperature region below 8 K. This compound is a metal complex which contains seven Cu(II)s in a cluster unit. These Cu(II)s are magnetically coupled each other by strong intra-complex interactions. The heat capacities under magnetic fields exhibit Schottky type anomalies explained by the Zeeman splitting of the doublet ground state of the complex. The g-value of the ground state is evaluated as 1.86 from the systematic analysis of the Schottky peak under magnetic fields. The first excited state of the cluster seems to be separated at least by several Kelvins, which is consistent with the theoretical calculations and magnetic susceptibility results. [ABSTRACT FROM AUTHOR]

Misfolding of superoxide dismutase-1 (SOD1) is a pathological hallmark of amyotrophic lateral sclerosis (ALS) with SOD1 mutations. The development of antibodies specific for misfolded SOD1 deepens our understanding of how the protein participates in ALS pathogenesis. Since the term "misfolding" refers to various disordered conformers other than the natively folded one, which misfolded species are recognized by specific antibodies should be determined. Here, we molecularly characterized the recognition by MS785-MS27, an antibody cocktail experimentally confirmed to recognize over 100 ALS-linked SOD1 mutants. Indirect ELISA revealed that the antibody cocktail recognized Zn-deficient wild-type and mutated SOD1 species. It also recognized conformation-disordered wild-type and mutated SOD1 species, such as unfolded and oligomeric forms, but had less affinity for the aggregated form. Antibody-reactive SOD1 exhibited cytotoxicity to a motor neuron cell model, which was blocked by Zn treatment with Zn-deficient SOD1. Immunohistochemistry revealed antibody-reactive SOD1 mainly in spinal motor neurons of SOD1 G93A mice throughout the disease course, and the distribution after symptomatic stages differed from that of other misfolded SOD1 species. This suggests that misfolded/non-native SOD1 species exist as heterogeneous populations. In conclusion, MS785-MS27 recognizes various conformation-disordered SOD1 species lacking the Zn ion.

Selenium is an essential trace element, and its deficiency can cause cardiomyopathy, arrhythmias and increased susceptibility to infection. Such clinical symptoms are considered primarily attributed to decreased expression of some of the 25 selenocysteine-containing selenoproteins in humans. Conversely, a selenium-excessive diet can cause acute poisoning and chronic symptoms with unknown mechanisms. To reveal the impact of selenium deficiency and excess on selenoprotein expression in vivo, mice (that possess 24 selenoproteins) were fed with selenium-deficient or selenomethionine-excessive diets for up to 4 weeks, and the expression levels of nine representative selenoproteins [glutathione peroxidase (Gpx) 1/2/3/4, thioredoxin reductase 1/2, deiodinase 1, and selenoprotein P/S] were measured in 10 organs (brain, heart, liver, lung, kidney, pancreas, spleen, testis, skeletal muscle and thymus). We observed a time-dependent decrease in the selenium content of most organs (except testis) of selenium-deficient mice but not in the expression levels of the nine selenoproteins, with the exceptions of Gpx1/2 in the heart/liver/kidney/pancreas/spleen and Gpx3 in the pancreas/spleen. Serum lipid peroxidation levels were up-regulated in response to Se deficiency because of the decreased expression/activity of Gpx3, a plasma-type Gpx. In contrast, a time-dependent increase was observed in the selenium content of all organs but not the expression levels of the nine selenoproteins in most organs of selenomethionine-excessive mice; however, markedly elevated protein-bound selenium levels were observed in the liver/kidney. These results suggest that the systemic response to selenium deficiency and selenomethionine excess involves the down-regulation of some selenoproteins such as Gpx1/Gpx3 and up-regulation of selenium-containing proteins (not selenoproteins), respectively., (Copyright © 2019 Elsevier Inc. All rights reserved.)

To elucidate insecticidal activity of spider toxins, metal ions in venoms and in the bodies were determined by thin layer chromatography, spark source mass spectrometry, ion chromatography, inductively coupled plasma emission spectrometry and atomic absorption spectrometry. Two kinds of spiders were used, Nephila clavata and Nephila maculata. Metals from their venom glands were extracted with hydrochloric acid and the metal concentrations were almost the same in the two species. Many kinds of metals, Fe, Zn, Pb, Cu, Ca, Mg, Na, P and S were found at higher levels in the venoms at concentrations higher than in the bodies. The contents of metal ions were low in the dragonfly and the cicada which are considered to be preys. Clavamine, the main insecticidal component in N. clavata, was effective on larvae of a mosquito with Ca2+, Fe3+ or Pb2+, but ineffective with Mg2+, Zn2+, Fe2+ or Cu2+. It is suggested that the metal chelates play an important role in the intoxication and detoxication of the spider toxins.