研究者詳細 - 前田　恵

論文 - 前田　恵

分割表示 103 件中 1 - 20 件目／全件表示 >>

Construction of tomato plants with suppressed endo-β-N-acetylglucosaminidase activity using CRISPR-Cas9 mediated genome editing. 査読国際誌

Naoko Okamoto, Megumi Maeda, Chiharu Yamamoto, Reo Kodama, Koichi Sugimoto, Yoshihito Shinozaki, Hiroshi Ezura, Yoshinobu Kimura

Plant physiology and biochemistry : PPB 190 203 - 211 2022年11月

記述言語：英語掲載種別：研究論文（学術雑誌）

High mannose-type free N-glycans with a single N-acetyl-D-glucosamine (GlcNAc) residue at the reducing end (GN1-HMT-FNGs) are produced by cytosolic endo-β-N-acetylglucosaminidase (EC:3.2.1.96) (ENGase) and are ubiquitous in differentiating and growing plant cells. To elucidate the physiological functions of HMT-FNGs in plants, we identified the ENGase gene in tomato (Solyc06g050930) and detected ENGase activity and increased production of GN1-HMT-FNGs during tomato fruit maturation. However, the precise role of GN1-HMT-FNGs in fruit maturation remains unclear. In this study, we established tomato ENGase mutants with suppressed ENGase activity via CRISPR/Cas9 genome editing technology. DNA sequencing of the Δeng mutants (T0 and T1 generations) revealed that they had the same mutations in the genomic DNA around the target sequences. Three null CRISPR/Cas9 segregant plants of the T1 generation (Δeng1-2, -22, and -26) were used to measure ENGase activity and analyze the structural features of HMT-FNGs in the leaves. The Δeng mutants did not exhibit ENGase activity and produced GN2-HMT-FNGs bearing tow GlcNAc residues at the reducing end side instead of GN1-HMT-FNGs. The Δeng mutants lack the N-terminal region of ENGase, indicating that the N-terminal region is important for full ENGase activity. The fruits of Δeng mutants (T2 generation) also showed loss of ENGase activity and similar structural features of HMT-FNGs of the T1 generation. However, there was no significant difference in fruit maturation between the T2 generation of the Δeng mutants and the wild type. The Δeng mutants rich in GN2-HMT-FNGs could be offered as a new tomato that is different from wild type containing GN1-HMT-FNGs.

DOI： 10.1016/j.plaphy.2022.08.009

Structural features of free N-glycans in α1,3/4-fucosidase-deficient Arabidopsis thaliana: deletion of α1,3/4-fucosidase activity induced accumulation of plant complex type GN1 free N-glycans. 査読国際誌

Shun Takata, Megumi Hayashi, Megumi Maeda, Takeshi Ishimizu, Yoshinobu Kimura

Bioscience, biotechnology, and biochemistry 86 ( 10 ) 1413 - 1416 2022年9月

記述言語：英語掲載種別：研究論文（学術雑誌）

Deletion of α-1,3/4-fucosidase activity in Arabidopsis thaliana resulted in the accumulation of GN1-type free N-glycans with the Lewis a epitope (GN1-FNG). This suggests that the release of α-fucose residue(s) may trigger rapid degradation of the plant complex-type (PCT) GN1-FNG. The fact that PCT-GN1-FNG has rarely been detected to date is probably due to its easier degradation compared with PCT-GN2-FNG.

DOI： 10.1093/bbb/zbac120

Improved method for preparation and purification of recombinant α-synuclein: high-mannose-type free N-glycan prepared from an edible bean (Vigna angulari, Azuki bean) inhibits α-synuclein aggregation. 査読国際誌

Shota Kosaka, Makoto Katsube, Megumi Maeda, Yoshinobu Kimura

Bioscience, biotechnology, and biochemistry 86 ( 6 ) 770 - 774 2022年5月

記述言語：英語掲載種別：研究論文（学術雑誌）

Parkinson's disease is characterized by the accumulation of amyloid, which consists of α-synuclein (α-Syn). To screen compounds with amyloid aggregation inhibitory activity, an effective method for the preparation of α-Syn is a prerequisite. We established a simpler method for α-Syn preparation using freeze-thaw treatment of transformed Escherichia coli. Furthermore, we found that the high-mannose type free N-glycans could prevent α-Syn aggregation.

DOI： 10.1093/bbb/zbac040

Improved assay system for acidic peptide: N-glycanase (aPNGase) activity in plant extracts. 査読国際誌

Chiharu Yamamoto, Mikako Ogura, Ryota Uemura, Maeda Megumi, Hiroyuki Kajiura, Ryo Misaki, Kazuhito Fujiyama, Yoshinobu Kimura

Analytical biochemistry 634 114367 - 114367 2021年12月

記述言語：英語掲載種別：研究論文（学術雑誌）

Plant acidic peptide: N-glycanase (aPNGase) release N-glycans from glycopeptides during the degradation process of glycoproteins in developing or growing plants. We have previously developed a new method to detect the aPNGase activity in crude extracts, which is prerequisite for the construction of aPNGase knockout or overexpression lines. However, this method has the disadvantage of requiring de-sialylation treatment and a lectin chromatography. In this study, therefore, we improved the simple and accurate method for detecting aPNGase activity using anion-exchange HPLC requiring neither the desialylation treatment nor the lectin affinity chromatography.

DOI： 10.1016/j.ab.2021.114367

Large-scale preparation of sialyl-Tn antigen-containing peptides from mucin-like glycoproteins in boar seminal gel. 査読国際誌

Ryota Takeuchi, Megumi Maeda, Miran Nakano, Hiroaki Funahashi, Yoshinobu Kimura

Bioscience, biotechnology, and biochemistry 85 ( 9 ) 2022 - 2025 2021年8月

記述言語：英語掲載種別：研究論文（学術雑誌）

Sialyl-Tn antigen, a tumor antigen, is a valuable ligand for the purification of proteins that specifically bind to it. Here, we developed a new method for the preparation of large amounts of sialyl-Tn antigen-containing peptides from an unused resource, boar seminal gel. The glycopeptides were prepared from the actinase E digests by a combination of gel filtration and hydrophilic partitioning.

DOI： 10.1093/bbb/zbab114

Purification, Characterization, and Gene Expression of Rice Endo-β-N-Acetylglucosaminidase, Endo-Os 査読国際誌

Megumi Maeda, Naoko Okamoto, Norie Araki, Yoshinobu Kimura

Frontiers in Plant Science 12 647684 - 647684 2021年8月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Frontiers Media SA

In the endoplasmic reticulum-associated degradation system of plant and animal cells, high-mannose type free <italic>N</italic>-glycans (HMT-FNGs) are produced from misfolded glycoproteins prior to proteasomal degradation, and two enzymes, cytosolic peptide:<italic>N</italic>-glycanase (cPNGase) and endo-β-<italic>N-</italic>acetylglucosaminidase (endo-β-GlcNAc-ase), are involved in the deglycosylation. Although the physiological functions of these FNGs in plant growth and development remain to be elucidated, detailed characterization of cPNGase and endo-β-GlcNAc-ase is required. In our previous work, we described the purification, characterization, and subcellular distribution of some plant endo-β-GlcNAc-ases and preliminarily reported the gene information of rice endo-β-GlcNAc-ase (Endo-Os). Furthermore, we analyzed the changes in gene expression of endo-β-GlcNAc-ase during tomato fruit maturation and constructed a mutant line of <italic>Arabidopsis thaliana</italic>, in which the two endo-β-GlcNAc-ase genes were knocked-out based on the Endo-Os gene. In this report, we describe the purification, characterization, amino acid sequence, and gene cloning of Endo-Os in detail. Purified Endo-Os, with an optimal pH of 6.5, showed high activity for high-mannose type <italic>N</italic>-glycans bearing the Manα1-2Manα1-3Manβ1 unit; this substrate specificity was almost the same as that of other plant endo-β-GlcNAc-ases, suggesting that Endo-Os plays a critical role in the production of HTM-FNGs in the cytosol. Electrospray ionization-mass spectrometry analysis of the tryptic peptides revealed 17 internal amino acid sequences, including the C terminus; the N-terminal sequence could not be identified due to chemical modification. These internal amino acid sequences were consistent with the amino acid sequence (UniProt ID: Q5W6R1) deduced from the <italic>Oryza sativa</italic> cDNA clone AK112067 (gene ID: <italic>Os05g0346500</italic>). Recombinant Endo-Os expressed in <italic>Escherichia coli</italic> using cDNA showed the same enzymatic properties as those of native Endo-Os.

DOI： 10.3389/fpls.2021.647684

Direct evidence of cytosolic PNGase activity in Arabidopsis thaliana: in vitro assay system for plant cPNGase activity 査読国際誌

Sahoko Shirai, Ryota Uemura, Megumi Maeda, Hiroyuki Kajiura, Ryo Misaki, Kazuhito Fujiyama, Yoshinobu Kimura

Bioscience, Biotechnology, and Biochemistry 85 ( 6 ) 1460 - 1463 2021年5月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Oxford University Press (OUP)

<title>ABSTRACT</title>
Cytosolic peptide:N-glycanase (cPNGase), which occurs ubiquitously in eukaryotic cells, is involved in the de-N-glycosylation of misfolded glycoproteins in the protein quality control system. In this study, we aimed to provide direct evidence of plant cPNGase activity against a denatured glycoprotein using a crude extract prepared from a mutant line of Arabidopsis thaliana lacking 2 acidic PNGase genes.

DOI： 10.1093/bbb/zbab047

その他リンク： http://academic.oup.com/bbb/article-pdf/85/6/1460/38192129/zbab047.pdf

Purification and molecular characterization of a truncated-type Ara h 1, a major peanut allergen: oligomer structure, antigenicity, and glycoform. 査読国際誌

Asaduzzaman Md, Megumi Maeda, Teruaki Matsui, Yoshihiro Takasato, Komei Ito, Yoshinobu Kimura

Glycoconjugate journal 38 ( 1 ) 67 - 76 2021年2月

記述言語：英語掲載種別：研究論文（学術雑誌）

Peanut allergies are among the most severe food allergies, and several allergenic proteins referred to as Ara h 1-Ara h 17 have been identified from peanut seeds. The molecular characterization of Ara h 1 (63 kDa), a glycosylated allergen, has almost been completed, and the occurrence of two homologous genes (clone 41B and clone P17) has been identified. In this study, we found a new variant of Ara h 1 i.e. 54 kDa, in which the N-terminal amino acid sequence was EGREGEQ-, indicating that the N-terminal domain of 63 kDa Ara h 1 had been removed. This new isoform was obtained from the run-through fraction of hydrophobic interaction chromatography while 63 kDa Ara h 1 was tightly bound to the hydrophobic resins, suggesting that the removal of the N-terminal domain resulted in extreme hydrophilic properties. We found that 63 kDa Ara h 1 occurs as higher order homo-oligomeric conformations such as decamer or nonamer, while 54 kDa Ara h 1 occurs exclusively as a homotrimer, indicating that the N-terminal domain of the 63 kDa molecule may be involved in higher order oligomerization. When antisera from peanut-allergic patients were treated with both the Ara h 1 molecules, the immunoglobulin E (IgE) antibodies in these sera reacted with each Ara h 1 molecule, suggesting that the C-terminal as well as the N-terminal domains of Ara h 1 contribute significantly to the epitope formations of this peanut glycoallergen. Furthermore, the glycoform analyses of N-glycans linked to 63 kDa and 54 kDa Ara h 1 subunits revealed that both typical high-mannose type and β-xylosylated type N-glycans are linked to the molecules. The cross-reactivity of IgE against Ara h 1 in the serum of one peanut allergy patient was completely lost by de-N-glycosylation, indicating the N-glycan of Ara h 1 was the sole epitope for the Ara h 1- specific IgE in the patient.

DOI： 10.1007/s10719-020-09969-1

Effect of asbestos exposure on differentiation and function of cytotoxic T lymphocytes. 査読国際誌

Naoko Kumagai-Takei, Yasumitsu Nishimura, Megumi Maeda, Hiroaki Hayashi, Hidenori Matsuzaki, Suni Lee, Kei Yoshitome, Tatsuo Ito, Takemi Otsuki

Environmental health and preventive medicine 25 ( 1 ) 59 - 59 2020年10月

記述言語：英語掲載種別：研究論文（学術雑誌）

Asbestos exposure is known to cause malignant mesothelioma, which is associated with poor prognosis. We focused on and examined the effect of asbestos exposure on the differentiation and function of cytotoxic T lymphocytes (CTLs). CTLs have the ability to specifically attack tumor cells after being differentiated from naïve CD8+ T cells following antigen stimulation. Exposure to chrysotile B asbestos suppressed the differentiation of CTLs during the mixed lymphocyte reaction (MLR) and was associated with a decrease in proliferation of CD8+ T cells. Additionally, in an effort to investigate the mechanism associated with suppressed CTL differentiation upon exposure to asbestos, we focused on IL-2, a cytokine involved in T cell proliferation. Our findings indicated that insufficient levels of IL-2 are not the main cause for the suppressed induction of CTLs by asbestos exposure, although they suggest potential improvement in the suppressed CTL function. Furthermore, the functional properties of peripheral blood CD8+ lymphocytes from asbestos-exposed individuals with pleural plaque (PP) and patients with malignant mesothelioma (MM) were examined. MM patients showed lower perforin levels in CD8+ lymphocytes following stimulation compared with PP-positive individuals. The production capacity of IFN-γ in the MM group tended to be lower compared with healthy volunteers or PP-positive individuals. In an effort to determine whether chronic and direct asbestos exposure affected the function of CD8+ T cells, cultured human CD8+ T cells were employed as an in vitro model and subjected to long-term exposure to chrysotile (CH) asbestos. This resulted in decreased levels of intracellular perforin and secreted IFN-γ. Those findings underlie the possibility that impaired CD8+ lymphocyte function is caused by asbestos exposure, which fail to suppress the development of MM. Our studies therefore reveal novel effects of asbestos exposure on CTLs, which might contribute towards the development and implementation of an effective strategy for the prevention and cure of malignant mesothelioma.

DOI： 10.1186/s12199-020-00900-6

Convenient preparation of an antigenic oligosaccharide from white kidney bean powder: A useful plant oligosaccharide for synthesis of immunoactive glycopolymer. 査読国際誌

Mariko Kimura, Mikako Ogura, Miyuki Akamatsu, Kaede Sugimoto, Megumi Maeda, Teruhiko Nitoda, Haruko Nagasawa-Fujimori, Hirotaka Yamashita, Yoshinobu Kimura

International journal of biological macromolecules 153 1016 - 1023 2020年6月

記述言語：英語掲載種別：研究論文（学術雑誌）

Plant glycoproteins, especially allergenic glycoproteins such as pollen allergens, often carry antigenic N-glycans with α1-3 fucose and/or β1-2 xylose residue(s) on the trimannosyl core structure. We previously reported that one of such antigenic free-form N-glycans, Man3Xyl1Fuc1GlcNAc2 (M3FX) suppressed IL-4 production from Th2 cells of pollinosis patients. For the molecular-level analysis of this immunoactivity, an effective and convenient procedure for large scale preparation of the immunoactive free-form N-glycan and a synthesis of glycopolymers bearing multivalent M3FX has been required. During the preparation of prebiotic oligosaccharides from several edible beans, we found that the free-form M3FX accumulates in relatively large amounts in white kidney beans. In this report, we describe a new procedure for preparation of M3FX from white kidney bean powders by a combination of ion-exchange method, gel-filtration, and hydrophilic partitioning. The high-purity of M3FX prepared by this procedure was confirmed by MS-analysis and 1H-NMR, suggesting that the free-form M3FX can be used for the synthesis of neoglycopolymer. Using this new procedure, the immunoactive oligosaccharide can be prepared without the chemical method such as hydrazinolysis and other purification steps required to exclude other type of N-glycans.

DOI： 10.1016/j.ijbiomac.2019.10.231

Synthesis and preliminary evaluation of neoglycopolymers carrying multivalent N-glycopeptide units. 査読国際誌

Naoto Takeda, Megumi Maeda, Satsuki Itano, Miho Takase, Mariko Kimura, Yoshinobu Kimura

International journal of biological macromolecules 147 1294 - 1300 2020年3月

記述言語：英語掲載種別：研究論文（学術雑誌）

In the present study, for the discovery of uncharacterized glycan-binding receptors or lectin-like receptors in plants, we developed neoglycopolymers to which three types of N-glycopeptides are conjugated; the first with plant complex type N-glycan (M3FX), the second with high-mannose type N-glycan (M8), and the third with animal complex type N-glycan (NeuAc2Gal2GN2M3). Three types of Asn-oligosaccharide (Asn-M3FX, Asn-M8, or Asn-NeuAc2Gal2GN2M3) were prepared from storage glycoproteins of Ginkgo biloba seeds, Vigna angularis seeds, and egg yolk glycopeptides from actinase digests of each glycoproteins or glycopeptide. Neoglycopolymers were synthesized such that the α-amino groups of Asn-oligosaccharide were coupled to the carboxyl groups of poly-γ-L-glutamic acid (γ-L-PGA) with 4-(4,6-Dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride n-hydrate (DMT-MM). The resulting neoglycopolymers were purified through a combination of gel-filtration and reverse-phase HPLC. The incorporation of N-glycans into γ-L-PGA (mol%) was estimated through amino acid composition analysis after acid hydrolysis. The incorporation rates of Asn-M3FX, Asn-M8, and Asn-NeuAc2Gal2GN2M3 into γ-L-PGA were 15.4%, 8.6%, and 11.1%, indicating that nearly 890, 500, and 640 molecules of N-glycans were conjugated with γ-L-PGA, respectively. Furthermore, we confirmed that the neoglycopolymer carrying the multivalent high-mannose type N-glycans is a useful tool for rapid purification of mannose-binding protein, Concanavalin A, from jack bean extract.

DOI： 10.1016/j.ijbiomac.2019.09.255

Cytosolic Free N-Glycans Are Retro-Transported Into the Endoplasmic Reticulum in Plant Cells. 査読国際誌

Makoto Katsube, Natsuki Ebara, Megumi Maeda, Yoshinobu Kimura

Frontiers in plant science 11 610124 - 610124 2020年

記述言語：英語掲載種別：研究論文（学術雑誌）

During endoplasmic reticulum (ER)-associated degradation, free N-glycans (FNGs) are produced from misfolded nascent glycoproteins via the combination of the cytosolic peptide N-glycanase (cPNGase) and endo-β-N-acetylglucosaminidase (ENGase) in the plant cytosol. The resulting high-mannose type (HMT)-FNGs, which carry one GlcNAc residue at the reducing end (GN1-FNGs), are ubiquitously found in developing plant cells. In a previous study, we found that HMT-FNGs assisted in protein folding and inhibited β-amyloid fibril formation, suggesting a possible biofunction of FNGs involved in the protein folding system. However, whether these HMT-FNGs occur in the ER, an organelle involved in protein folding, remained unclear. On the contrary, we also reported the presence of plant complex type (PCT)-GN1-FNGs, which carry the Lewisa epitope at the non-reducing end, indicating that these FNGs had been fully processed in the Golgi apparatus. Since plant ENGase was active toward HMT-N-glycans but not PCT-N-glycans that carry β1-2xylosyl and/or α1-3 fucosyl residue(s), these PCT-GN1-FNGs did not appear to be produced from fully processed glycoproteins that harbored PCT-N-glycans via ENGase activity. Interestingly, PCT-GN1-FNGs were found in the extracellular space, suggesting that HMT-GN1-FNGs formed in the cytosol might be transported back to the ER and processed in the Golgi apparatus through the protein secretion pathway. As the first step in elucidating the production mechanism of PCT-GN1-FNGs, we analyzed the structures of free oligosaccharides in plant microsomes and proved that HMT-FNGs (Man9-7GlcNAc1 and Man9-8GlcNAc2) could be found in microsomes, which almost consist of the ER compartments.

DOI： 10.3389/fpls.2020.610124

Plant complex type free N-glycans occur in tomato xylem sap. 査読国際誌

Yuta Tsujimori, Mikako Ogura, Md Ziaur Rahman, Megumi Maeda, Yoshinobu Kimura

Bioscience, biotechnology, and biochemistry 83 ( 7 ) 1310 - 1314 2019年7月

記述言語：英語掲載種別：研究論文（学術雑誌）

Free N-glycans (FNGs) are ubiquitous in growing plants. Further, acidic peptide:N-glycanase is believed to be involved in the production of plant complex-type FNGs (PCT-FNGs) during the degradation of dysfunctional glycoproteins. However, the distribution of PCT-FNGs in growing plants has not been analyzed. Here, we report the occurrence of PCT-FNGs in the xylem sap of the stem of the tomato plant. Abbreviations: RP-HPLC: reversed-phase HPLC; SF-HPLC: size-fractionation HPLC; PA-: pyridylamino; PCT: plant complex type; Hex: hexose; HexNAc: N-acetylhexosamine; Pen: pentose; Deoxyhex: deoxyhexose; Man: D-mannose; GlcNAc: N-acetyl-D-glucosamine; Xyl: D-xylose; Fuc: L-fucose; Lea: Lewis a (Galβ1-3(Fucα1-4)GlcNAc); PCT: plant complex type; M3FX: Manα1-6(Manα1-3)(Xylβ1-2)Manβ1-4GlcNAcβ1-4(Fucα1-3)GlcNAc-PA; GN2M3FX: GlcNAcβ1-2Manα1-6(GlcNAcβ1-2Manα1-3)(Xylβ1-2)Manβ1-4GlcNAcβ1-4(Fucα1-3)GlcNAc-PA; (Lea)1GN1M3FX: Galβ1-3(Fucα1-4)GlcNAc1-2 Manα1-6(GlcNAcβ1-2Manα1-3)(Xylβ1-2)Manβ1-4GlcNAcβ1-4(Fucα1-3)GlcNAc-PA or GlcNAc1-2Manα1-6(Galβ1-3(Fucα1-4)GlcNAc1-2Manα1-3)(Xylβ1-2)Manβ1-4GlcNAcβ1-4(Fucα1-3)GlcNAc-PA.

DOI： 10.1080/09168451.2019.1608803

アスベスト曝露によるヒト末梢血CD4+細胞からのIL-17産生誘導

大槻剛巳, 前田恵, 李順姫, 吉留敬, 武井直子, 西村泰光

産業衛生学雑誌 61 ( 臨増 ) 444 - 444 2019年5月

Aberrant expression of FoxP3 in a human T cell line possessing regulatory T cell‑like function and exposed continuously to asbestos fibers. 査読国際誌

Maeda M, Matsuzaki H, Yamamoto S, Lee S, Kumagai-Takei N, Yoshitome K, Min Y, Sada N, Nishimura Y, Otsuki T

Oncology reports 40 ( 2 ) 748 - 758 2018年8月

Molecular characterization of second tomato α1,3/4-fucosidase (α-Fuc'ase Sl-2), a member of glycosyl hydrolase family 29 active toward the core α1,3-fucosyl residue in plant N-glycans. 査読国際誌

Md Ziaur Rahman, Yuta Tsujimori, Megumi Maeda, Md Anowar Hossain, Takeshi Ishimizu, Yoshinobu Kimura

Journal of biochemistry 164 ( 1 ) 53 - 63 2018年7月

記述言語：英語掲載種別：研究論文（学術雑誌）

In a previous study, we molecular-characterized a tomato (Solanum lycopersicum) α1, 3/4-fucosidase (α-Fuc'ase Sl-1) encoded in a tomato gene (Solyc03g006980), indicating that α-Fuc'ase Sl-1 is involved in the turnover of Lea epitope-containing N-glycans. In this study, we have characterized another tomato gene (Solyc11g069010) encoding α1, 3/4-fucosidase (α-Fuc'ase Sl-2), which is also active toward the complex type N-glycans containing Lea epitope(s). The baculovirus-insect cell expression system was used to express that α-Fuc'ase Sl-2 with anti-FLAG tag, and the expression product (rFuc'ase Sl-2), was found as a 65 kDa protein using SDS-PAGE and has an optimum pH of around 5.0. Similarly to rFuc'ase Sl-1, rFuc'ase Sl-2 hydrolyzed the non-reducing terminal α1, 3-fucose residue on LNFP III and α1, 4-fucose residues of Lea epitopes on plant complex type N-glycans, but not the core α1, 3-fucose residue on Manβ1-4GlcNAcβ1-4(Fucα1-3)GlcNAc or Fucα1-3GlcNAc. However, we found that both α-Fuc'ases Sl-1 and Sl-2 were specifically active toward α1, 3-fucose residue on GlcNAcβ1-4(Fucα1-3)GlcNAc, indicating that the non-substituted β-GlcNAc linked to the proximal GlcNAc residue of the core tri-saccharide moiety of plant specific N-glycans must be a pre-requisite for α-Fuc'ase activity. A 3 D modelled structure of the catalytic sites of α-Fuc'ase Sl-2 suggested that Asp192 and Glu236 may be important for binding to the α1, 3/4 fucose residue.

DOI： 10.1093/jb/mvy029

Novel assay system for acidic Peptide:N-glycanase (aPNGase) activity in crude plant extract. 査読国際誌

Ryota Uemura, Mikako Ogura, Chihiro Matsumaru, Tsuyoshi Akiyama, Megumi Maeda, Yoshinobu Kimura

Bioscience, biotechnology, and biochemistry 82 ( 7 ) 1172 - 1175 2018年7月

記述言語：英語掲載種別：研究論文（学術雑誌）

Acidic peptide:N-glycanase (aPNGase) plays a pivotal role in plant glycoprotein turnover. For the construction of aPNGase-knockout or -overexpressing plants, a new method to detect the activity in crude plant extracts is required because endogenous peptidases present in the extract hamper enzyme assays using fluorescence-labeled N-glycopeptides as a substrate. In this study, we developed a new method for measuring aPNGase activity in crude extracts from plant materials.

DOI： 10.1080/09168451.2018.1459464

Inflammatory Alteration of Human T Cells Exposed Continuously to Asbestos. 査読国際誌

Kumagai-Takei N, Yamamoto S, Lee S, Maeda M, Masuzzaki H, Sada N, Yu M, Yoshitome K, Nishimura Y, Otsuki T

International journal of molecular sciences 19 ( 2 ) 2018年2月

Degradation pathway of plant complex-type n-glycans: Identification and characterization of a key α1,3-fucosidase from glycoside hydrolase family 29 査読国際誌

Shun Kato, Megumi Hayashi, Mai Kitagawa, Hiroyuki Kajiura, Megumi Maeda, Yoshinobu Kimura, Kiyohiko Igarashi, Masahiro Kasahara, Takeshi Ishimizu

Biochemical Journal 475 ( 1 ) 305 - 317 2018年1月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Portland Press Ltd

Plant complex-type N-glycans are characterized by the presence of α1,3-linked fucose towards the proximal N-acetylglucosamine residue and β1,2-linked xylose towards the β-mannose residue. These glycans are ultimately degraded by the activity of several glycoside hydrolases. However, the degradation pathway of plant complex-type N-glycans has not been entirely elucidated because the gene encoding α1,3-fucosidase, a glycoside hydrolase acting on plant complex-type N-glycans, has not yet been identified, and its substrate specificity remains to be determined. In the present study, we found that AtFUC1 (an Arabidopsis GH29 α-fucosidase) is an α1,3-fucosidase acting on plant complex-type N-glycans. This fucosidase has been known to act on α1,4-fucoside linkage in the Lewis A epitope of plant complex-type N-glycans. We found that this glycoside hydrolase specifically acted on GlcNAcβ1–4(Fucα1–3)GlcNAc, a degradation product of plant complex-type N-glycans, by sequential actions of vacuolar α-mannosi-dase, β1,2-xylosidase, and endo-β-mannosidase. The AtFUC1-deficient mutant showed no distinct phenotypic plant growth features
however, it accumulated GlcNAcβ1–4 (Fucα1–3)GlcNAc, a substrate of AtFUC1. These results showed that AtFUC1 is an α1,3-fucosidase acting on plant complex-type N-glycans and elucidated the degradation pathway of plant complex-type N-glycans.

DOI： 10.1042/BCJ20170106

Skewing T helper cells exposed to asbestos fibers toward reduction of tumor immunity or activation of autoimmunity 査読

Kumagai-Takei N, Lee S, Matsuzaki H, Maeda M, Yu M, Sada N, Yoshitome K, Nishimura Y, Otsuki T

Kawasaki Med J 44 ( 4 ) 33 - 40 2018年

　前のページ - 次のページ　

1
2
3
4
5
6