Publications by authors named "Takafumi Itoh"

A method to more easily separate vascular bundles and parenchyma was investigated for the purpose of proposing a sustainable and advanced utilization of oil palm trunk (OPT). In addition, particleboard made from vascular bundles was produced as one of the effective ways to utilize the obtained vascular bundles. The following results were obtained.

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The chitinolytic bacterium sp. str. FPU-7 efficiently degrades chitin into oligosaccharides such as -acetyl-D-glucosamine (GlcNAc) and disaccharides (GlcNAc) through multiple secretory chitinases.

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Chitin and its derivatives have valuable potential applications in various fields that include medicine, agriculture, and food industries. Paenibacillus sp. str.

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α-1,3-Glucanase from Streptomyces thermodiastaticus HF3-3 (Agl-ST) has been classified in the glycoside hydrolase (GH) family 87. Agl-ST is a multi-modular domain consisting of an N-terminal β-sandwich domain (β-SW), a catalytic domain, an uncharacterized domain (UC), and a C-terminal discoidin domain (DS). Although Agl-ST did not hydrolyze α-1,4-glycosidic bonds, its amino acid sequence is more similar to GH87 mycodextranase than to α-1,3-glucanase.

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γ-Glutamyltranspeptidase (GGT) is a ubiquitous enzyme that catalyzes the hydrolysis of the γ-glutamyl linkage of γ-glutamyl compounds and the transfer of their γ-glutamyl moiety to acceptor substrates. Pseudomonas nitroreducens GGT (PnGGT) is used for the industrial synthesis of theanine, thus it is important to determine the structural basis of hydrolysis and transfer reactions and identify the acceptor site of PnGGT to improve the efficient of theanine synthesis. Our previous structural studies of PnGGT have revealed that crucial interactions between three amino acid residues, Trp385, Phe417, and Trp525, distinguish PnGGT from other GGTs.

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α-1,3-Glucan is a homopolymer composed of D-glucose (Glc) and it is an extracellular polysaccharide found in dental plaque due to Streptococcus species. α-1,3-Glucanase from Streptomyces thermodiastaticus strain HF3-3 (Agl-ST) has been identified as a thermostable α-1,3-glucanase, which is classified into glycoside hydrolase family 87 (GH87) and specifically hydrolyzes α-1,3-glucan with an endo-action. The enzyme has a potential to inhibit the production of dental plaque and to be used for biotechnological applications.

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Urate oxidases (UOs) catalyze the cofactor-independent oxidation of uric acid, and an extensive water network in the active site has been suggested to play an essential role in the catalysis. For our present analysis of the structure and function of the water network, the crystal qualities of Bacillus sp. TB-90 urate oxidase were improved by controlled dehydration using the humid air and glue-coating method.

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The plasma membrane regulates biological processes such as ion transport, signal transduction, endocytosis, and cell differentiation/proliferation. To understand the functional characteristics and organ specificity of plasma membranes, plasma membrane protein fractions from rice root, etiolated leaf, green leaf, developing leaf sheath, and flower were analyzed by proteomics. Among the proteins identified, 511 were commonly accumulated in the five organs, whereas 270, 132, 359, 146, and 149 proteins were specifically accumulated in the root, etiolated leaf, green leaf, developing leaf sheath, and developing flower, respectively.

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The α-1,3-glucanase from Paenibacillus glycanilyticus FH11 (Agl-FH1), a member of the glycoside hydrolase family 87 (GH87), hydrolyzes α-1,3-glucan with an endo-action. GH87 enzymes are known to degrade dental plaque produced by oral pathogenic Streptococcus species. In this study, the kinetic analyses revealed that this enzyme hydrolyzed α-1,3-tetraglucan into glucose and α-1,3-triglucan with β-configuration at the reducing end by an inverting mechanism.

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Glycoside hydrolase (GH) 87-type α-1,3-glucanase hydrolyses the α-1,3-glucoside linkages of α-1,3-glucan, which is found in fungal cell walls and extracellular polysaccharides produced by oral Streptococci. In this study, we report on the molecular structure of the catalytic unit of GH 87-type α-1,3-glucanase, Agl-KA, from Bacillus circulans, as determined by x-ray crystallography at a resolution of 1.82 Å.

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A novel alginate lyase, PsAly, with a molecular mass of 33 kDa and whose amino acid sequence shares no significant similarity to other known proteins, was biochemically and structurally characterised from Paenibacillus sp. str. FPU-7.

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Chitin, a β-1,4-linked homopolysaccharide of N-acetyl-d-glucosamine (GlcNAc), is one of the most abundant biopolymers on Earth. Paenibacillus sp. str.

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Chitin, a structural polysaccharide of β-1,4-linked N-acetyl-D-glucosamine residues, is the second most abundant natural biopolymer after cellulose. The metabolism of chitin affects the global carbon and nitrogen cycles, which are maintained by marine and soil-dwelling bacteria. The degradation products of chitin metabolism serve as important nutrient sources for the chitinolytic bacteria.

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The currently available haemoglobin A1c (HbA1c) enzymatic assay consists of two specific steps: proteolysis of HbA1c and oxidation of the liberated fructosyl peptide by fructosyl peptide oxidase (FPOX). To develop a more convenient and high throughput assay, we devised novel protease-free assay system employing modified FPOX with HbA1c oxidation activity, namely HbA1c direct oxidase (HbA1cOX). AnFPOX-15, a modified FPOX from Aspergillus nidulans, was selected for conversion to HbA1cOX.

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Theanine (γ-glutamylethylamide) is an amino acid analog that reduces blood pressure and improves immune responses. The ϒ-glutamyltranspeptidase (GGT) from Pseudomonas nitroreducens IFO12694 (PnGGT) has a unique preference for primary amines as ϒ-glutamyl acceptors over standard L-amino acids and peptides. This characteristic is useful for the synthesis of theanine.

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α-1,3-Glucanase hydrolyzes α-1,3-glucan, an insoluble linear α-1,3-linked homopolymer of glucose that is found in the extracellular polysaccharides produced by oral streptococci in dental plaque and in fungal cell walls. This enzyme could be of application in dental care and the development of fungal cell-wall lytic enzymes, but its three-dimensional structure has not been available to date. In this study, the recombinant catalytic domain of α-1,3-glucanase FH1 from Paenibacillus glycanilyticus FH11, which is classified into glycoside hydrolase family 87, was prepared using a Brevibacillus choshinensis expression system and purified in a soluble form.

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Heterotrimeric G proteins are the molecule switch that transmits information from external signals to intracellular target proteins in mammals and yeast cells. In higher plants, heterotrimeric G proteins regulate plant architecture. Rice harbors one canonical α subunit gene (), four extra-large GTP-binding protein genes (XLGs), one canonical β-subunit gene (), and five γ-subunit genes (tentatively designated , , ///, ////, and /) as components of the heterotrimeric G protein complex.

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Heterotrimeric G proteins are important molecules for regulating plant architecture and transmitting external signals to intracellular target proteins in higher plants and mammals. The rice genome contains one canonical α subunit gene (), four extra-large GTP-binding protein genes (XLGs), one canonical β subunit gene ), and five γ subunit genes (tentatively named , , , , and ). encodes the canonical γ subunit; encodes the plant-specific type of γ subunit with additional amino acid residues at the N-terminus; and the remaining three γ subunit genes encode the atypical γ subunits with cysteine abundance at the C-terminus.

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Unlabelled: Plant-derived smoke plays a key role in seed germination and plant growth. To investigate the effect of plant-derived smoke on chickpea, a gel-free/label-free proteomic technique was used. Germination percentage, root/shoot length, and fresh biomass were increased in chickpea treated with 2000 ppm plant-derived smoke within 6 days.

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The wheat florigen gene Wheat FLOWERING LOCUS T (WFT, which is identical to VRN3) is an integrator of the vernalization, photoperiod and autonomous pathways in wheat flowering. Many studies have indicated that VERNALIZATION 1 (VRN1) directly or indirectly up-regulates WFT expression in leaves. VRN1 encodes an APETALA1/FRUITFULL-like MADS box transcription factor that is up-regulated by vernalization and aging, leading to promotion of flowering.

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Bacillus sp. TB-90 urate oxidase (BTUO) is one of the most thermostable homotetrameric enzymes. We previously reported [Hibi, T.

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A colorimetric method for monosaccharide determination (Anal. Sci., 2013, 29, 1021) was optimized for the high-throughput screening of α-glucosidase, which hydrolyzes an α-1,4-glycosidic bond of starch and related oligo- and polysaccharides, followed by the release of D-glucose from the non-reducing ends.

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The acidic polysaccharide alginate represents a promising marine biomass for the microbial production of biofuels, although the molecular and structural characteristics of alginate transporters remain to be clarified. In Sphingomonas sp. A1, the ATP-binding cassette transporter AlgM1M2SS is responsible for the import of alginate across the cytoplasmic membrane.

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