291 research outputs found

    Bovine Insulin Filaments Induced by Reducing Disulfide Bonds Show a Different Morphology, Secondary Structure, and Cell Toxicity from Intact Insulin Amyloid Fibrils

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    AbstractAmyloid fibrils are associated with more than 20 diseases, including Alzheimer's disease and type II diabetes. Insulin is a 51-residue polypeptide hormone, with its two polypeptide chains linked by one intrachain and two interchain disulfide bonds, and has long been known to self-assemble in vitro into amyloid fibrils. We demonstrate here that bovine insulin forms flexible filaments in the presence of a reducing agent, Tris (2-carboxyethyl) phosphine. The insulin filaments, possibly formed due to partial reduction of S-S bonds in insulin molecules, differ from intact insulin fibrils in terms of their secondary structure. The insulin filaments were determined to have an antiparallel β-sheet structure, whereas the insulin fibrils have a parallel β-sheet structure. Of importance, the cell toxicity of the insulin filaments was remarkably lower than that of the insulin fibrils. This finding supports the idea that cell toxicity of amyloids correlates with their morphology. The remarkably low toxicity of the filamentous structure should shed new light on possible pharmacological approaches to the various diseases caused by amyloid fibrils

    A METHOD FOR ESTIMATING ELBOW VARUS TORQUE USING ONLY A BASEBALL WITH AN EMBEDDED SENSOR

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    Currently, to measure the elbow varus torque during baseball pitching, it is necessary to attach markers and sensors to the body. The purpose of this study is to develop the method for estimating elbow varus torque by only a baseball with an embedded sensor, and examine the accuracy. Eight baseball pitchers threw a four-seam fastball with maximum effort. The varus torque was estimated using one-link-segment model by an accelerometer and gyro sensor placed in the baseball. The Intraclass Correlation Coefficients between the maximum values of the varus torque calculated by the proposed method and the values calculated by the motion capture system was high (ICC(3,1) = 0.73).This result indicates that proof of concept by one-link model is success and warrants future research to potentially develop a system with greater accuracy

    Functional expression of thiocyanate hydrolase is promoted by its activator protein, P15K

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    AbstractThiocyanate hydrolase (SCNase) is a cobalt-containing enzyme with a post-translationally modified cysteine ligand, γCys131-SO2H. When the SCNase α, β and γ subunits were expressed in Escherichia coli, the subunits assembled to form a hetero-dodecamer, (αβγ)4, like native SCNase but exhibited no catalytic activity. Metal analysis indicated that SCNase was expressed as an apo-form irrespective of the presence of cobalt in the medium. On the contrary, SCNase co-expressed with P15K, encoded just downstream of SCNase genes, in cobalt-enriched medium under the optimized condition (SCNase(+P15K)) possessed 0.86 Co atom/αβγ trimer and exhibited 78% of the activity of native SCNase. SCNase(+P15K) showed a UV–Vis absorption peak characteristic of the SCNase cobalt center. About 70% of SCNase(+P15K) had the γCys131-SO2H modification. These results indicate that SCNase(+P15K) is the active holo-SCNase. P15K is likely to promote the functional expression of SCNase probably by assisting the incorporation of cobalt ion

    Application of Electron Beam Melting to the Removal of Phosphorus from Silicon: Toward Production of Solar-Grade Silicon by Metallurgical Processes

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    Removal methods of impurity from metallurgical-grade silicon (Si) are intensively studied to produce solar-grade silicon (SoG-Si) with a smaller economical load and lower cost. Removal of phosphorus (P) has been an important issue because of difficulties in application of conventional metallurgical methods such as solidification refining. Because P evaporates preferentially from molten Si due to its high vapor pressure, electron beam (EB) melting has been applied to the purification of Si. The evaporation of impurity P from Si is considered based on previous thermodynamic investigations here, and several research reports on EB melting of Si are reviewed

    地域課題解決学習による児童の挑戦する意欲と社会的有効性意識の向上 : 総合的な学習の時間のマネジメントと授業実践を通して

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    The purpose of this study is to examine the effects of teachers’ the period for the Period of Integrated Study management and class practice, which mainly focuses on solving the problems of the community, on children’s willingness to take on challenges and awareness of social effectiveness in elementary schools. A graduate student who is also an elementary school teacher managed the Period of Integrated Study and practiced the lesson for about one year, mainly focusing on solving the problems of the community for 4th to 6th graders. A questionnaire survey was conducted before and after the practice to measure the children’s willingness to take on challenges and awareness of social effectiveness. As a result, under certain conditions, it was found that, in elementary schools, teachers’ the Period of Integrated Study management and class practice, which mainly focuses on solving the problems of the community can increase children’s willingness to take on challenges and a sense of social effectiveness. The condition is that the children have the experience of directly changing to solve the problems of the community continuously together with the residents who work to solve the problems of the community
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