260 research outputs found

    Venomics Study of <em>Protobothrops flavoviridis</em> Snake: How Venom Proteins Have Evolved and Diversified?

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    Venomics projects have been conducted to disclose the divergent profiles and evolution of various venomous animals. Here, we describe the venomics project including genome and transcriptome of habu snake, leading to drug discovery. Venomics project including the decoding of their whole genomes revealed partly a producing mechanism of various venom proteins including accelerated evolution and alternative splicing and how the toxic organisms have evolved from the nontoxic ones. In addition, the venomics analysis of transcriptomes and proteomes beyond species reveals the relationship between the geographical distribution and evolution of toxic organisms. The abundance of different gene products within a gene family caused by accelerated evolution and alternative splicing may contribute to expand the repertoire of effective weapons to prey capture accompanied with neofunctionalization

    Structures and Functions of C-type Lectins in Marine Invertebrates

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    Lectins distributing in all animal phyla form a diverse group of protein families that have in common the ability to recognize and bind certain carbohydrates. Although at least 13 animal lectin families are known to exist, many of marine invertebrate lectins are categorized in C-type lectin family, which was named from the Ca^-dependency for their carbohydrate binding activities. In contrast to a growing list of C-type lectins in marine invertebrates, their physiological roles are not fully understood. This review summarizes the structures and functions of marine invertebrate C-type lectins with our new findings

    Diversified Carbohydrate-Binding Lectins from Marine Resources

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    Marine bioresources produce a great variety of specific and potent bioactive molecules including natural organic compounds such as fatty acids, polysaccharides, polyether, peptides, proteins, and enzymes. Lectins are also one of the promising candidates for useful therapeutic agents because they can recognize the specific carbohydrate structures such as proteoglycans, glycoproteins, and glycolipids, resulting in the regulation of various cells via glycoconjugates and their physiological and pathological phenomenon through the host-pathogen interactions and cell-cell communications. Here, we review the multiple lectins from marine resources including fishes and sea invertebrate in terms of their structure-activity relationships and molecular evolution. Especially, we focus on the unique structural properties and molecular evolution of C-type lectins, galectin, F-type lectin, and rhamnose-binding lectin families

    Improved Formalism for Precision Higgs Coupling Fits

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    Future e+e- colliders give the promise of model-independent determinations of the couplings of the Higgs boson. In this paper, we present an improved formalism for extracting Higgs boson couplings from e+e- data, based on the Effective Field Theory description of corrections to the Standard Model. We apply this formalism to give projections of Higgs coupling accuracies for stages of the International Linear Collider and for other proposed e+e- colliders.Comment: 34 pages, 4 figures; v4: clarifications and new references added; v5, additional references adde

    Protein engineering of conger eel galectins by tracing of molecular evolution using probable ancestral mutants

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    <p>Abstract</p> <p>Background</p> <p>Conger eel galectins, congerin I (ConI) and congerin II (ConII), show the different molecular characteristics resulting from accelerating evolution. We recently reconstructed a probable ancestral form of congerins, Con-anc. It showed properties similar to those of ConII in terms of thermostability and carbohydrate recognition specificity, although it shares a higher sequence similarity with ConI than ConII.</p> <p>Results</p> <p>In this study, we have focused on the different amino acid residues between Con-anc and ConI, and have performed the protein engineering of Con-anc through site-directed mutagenesis, followed by the molecular evolution analysis of the mutants. This approach revealed the functional importance of loop structures of congerins: (1) N- and C-terminal and loop 5 regions that are involved in conferring a high thermostability to ConI; (2) loops 3, 5, and 6 that are responsible for stronger binding of ConI to most sugars; and (3) loops 5 and 6, and Thr38 residue in loop 3 contribute the specificity of ConI toward lacto-<it>N</it>-fucopentaose-containing sugars.</p> <p>Conclusions</p> <p>Thus, this methodology, with tracing of the molecular evolution using ancestral mutants, is a powerful tool for the analysis of not only the molecular evolutionary process, but also the structural elements of a protein responsible for its various functions.</p

    A novel technique for the measurement of the avalanche fluctuation of gaseous detectors

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    We have developed a novel technique for the measurement of the avalanche fluctuation of gaseous detectors using a UV laser. The technique is simple and requires a short data-taking time of about ten minutes. Furthermore, it is applicable for relatively low gas gains. Our experimental setup as well as the measurement principle, and the results obtained with a stack of Gas Electron Multipliers (GEMs) operated in several gas mixtures are presented.Comment: 7 pages, 7 figures. For the proceedings of VCI2016, to be published in Nucl. Instrum. Methods Phys. Res.

    Urinary Fetuin-A Is a Novel Marker for Diabetic Nephropathy in Type 2 Diabetes Identified by Lectin Microarray

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    We analyzed the urine samples of patients with type 2 diabetes at various stages of diabetic nephropathy by lectin microarray to identify a biomarker to predict the progression of diabetic nephropathy. Japanese patients with type 2 diabetes at various stages of nephropathy were enrolled and we performed lectin microarray analyses (n = 17) and measured urinary excretion of fetuin-A (n = 85). The increased signals of urine samples were observed in Sia alpha 2-6Gal/GalNAc-binding lectins (SNA, SSA, TJA-I) during the progression of diabetic nephropathy. We next isolated sialylated glycoproteins by using SSA-lectin affinity chromatography and identified fetuin-A by liquid chromatography-tandem mass spectrometer. Urinary excretion of fetuin-A significantly increased during the progression of albuminuria (A1, 0.40 +/- 0.43; A2, 0.60 +/- 0.53; A3 1.57 +/- 1.13 ng/gCr; p = 7.29x10(-8)) and of GFR stages (G1, 0.39 +/- 0.39; G2, 0.49 +/- 0.45; G3, 1.25 +/- 1.18; G4, 1.34 +/- 0.80 ng/gCr; p = 3.89x10(-4)). Multivariate logistic regression analysis was employed to assess fetuin-A as a risk for diabetic nephropathy with microalbuminuria or GFR<60 mL/min. Fetuin-A is demonstrated as a risk factor for both microalbuminuria and reduction of GFR in diabetic nephropathy with the odds ratio of 4.721 (1.881-11.844) and 3.739 (1.785-7.841), respectively. Collectively, the glycan profiling analysis is useful method to identify the urine biomarkers and fetuin-A is a candidate to predict the progression of diabetic nephropathy

    CHAC1 overexpression in human gastric parietal cells with Helicobacter pylori infection in the secretory canaliculi

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    Background Cation transport regulator 1 (CHAC1), a newly discovered enzyme that degrades glutathione, is induced in Helicobacter pylori (H. pylori)‐infected gastric epithelial cells in culture. The CHAC1‐induced decrease in glutathione leads to an accumulation of reactive oxygen species and somatic mutations in TP53. We evaluated the possible correlation between H. pylori infection and CHAC1 expression in human gastric mucosa. Materials and Methods Both fresh‐frozen and formalin‐fixed paraffin‐embedded tissue samples of gastric mucosa with or without H. pylori infection were obtained from 41 esophageal cancer patients that underwent esophago‐gastrectomy. Fresh samples were used for real‐time polymerase chain reaction for H. pylori DNA and CHAC1 mRNA, and formalin‐fixed samples were used for immunohistochemistry with anti‐CHAC1 and anti‐H. pylori monoclonal antibodies. Double‐enzyme or fluorescence immunohistochemistry and immuno‐electron microscopy were used for further analysis. Results Significant CHAC1 overexpression was detected in H. pylori‐infected parietal cells that expressed the human proton pump/H,K‐ATPase α subunit, whereas a constitutively low level of CHAC1 mRNA expression was observed in the other samples regardless of the H. pylori infection status, reflecting the weak CHAC1 expression detected by immunohistochemistry in the fundic‐gland areas. Immuno‐electron microscopy revealed intact H. pylori cells in the secretory canaliculi of infected parietal cells. Some parietal cells exhibited positive nuclear signals for Ki67 in the neck zone of the gastric fundic‐gland mucosa with H. pylori infection. Conclusion Cation transport regulator 1 overexpression in H. pylori‐infected parietal cells may cause the H. pylori‐induced somatic mutations that contribute to the development of gastric cancer.This work was supported by the Japan Society for the Promotion of Science KAKENHI (16K19077), and by the Practical Research for Innovative Cancer Control from Japan Agency for Medical Research and development, AMED
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