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137 results on '"Nemoto, Michiko"'

2. Radular stylus of Cryptochiton stelleri: A multifunctional lightweight and flexible fiber-reinforced composite

Author

Pohl, Anna, Herrera, Steven A, Restrepo, David, Negishi, Ryo, Jung, Jae-Young, Salinas, Chris, Wuhrer, Richard, Yoshino, Tomoko, McKittrick, Joanna, Arakaki, Atsushi, Nemoto, Michiko, Zavattieri, Pablo, and Kisailus, David

Subjects
Engineering, Materials Engineering, Animals, Ferrosoferric Oxide, Microscopy, Electron, Polyplacophora, Tooth, Mollusk, Biocomposite, Force transduction, Flexible, Biomedical Engineering, Mechanical Engineering, Biomedical engineering, Materials engineering, Mechanical engineering
Abstract

Chitons are herbivorous invertebrates that use rows of ultrahard magnetite-based teeth connected to a flexible belt (radula) to rasp away algal deposits growing on and within rocky outcrops along coastlines around the world. Each tooth is attached to the radula by an organic structure (stylus) that provides mechanical support during feeding. However, the underlying structures within the stylus, and their subsequent function within the chiton have yet to be investigated. Here, we investigate the macrostructural architecture, the regional material and elemental distribution and subsequent nano-mechanical properties of the stylus from the Northern Pacific dwelling Cryptochiton stelleri. Using a combination of μ-CT imaging, optical and electron microscopy, as well as elemental analysis, we reveal that the stylus is a highly contoured tube, mainly composed of alpha-chitin fibers, with a complex density distribution. Nanoindentation reveals regiospecific and graded mechanical properties that can be correlated with both the elemental composition and material distribution. Finite element modeling shows that the unique macroscale architecture, material distribution and elemental gradients have been optimized to preserve the structural stability of this flexible, yet robust functionally-graded fiber-reinforced composite tube, providing effective function during rasping. Understanding these complex fiber-based structures offers promising blueprints for lightweight, multifunctional and integrated materials.

Published
2020

3. Integrated transcriptomic and proteomic analyses of a molecular mechanism of radular teeth biomineralization in Cryptochiton stelleri.

Author

Nemoto, Michiko, Ren, Dongni, Herrera, Steven, Pan, Songqin, Tamura, Takashi, Inagaki, Kenji, and Kisailus, David

Subjects
Animals, Biomineralization, Calcification, Physiologic, Ferritins, Ferrosoferric Oxide, Globins, Polyplacophora, Proteomics, Tooth, Tooth Calcification, Transcriptome
Abstract

Many species of chiton are known to deposit magnetite (Fe3O4) within the cusps of their heavily mineralized and ultrahard radular teeth. Recently, much attention has been paid to the ultrastructural design and superior mechanical properties of these radular teeth, providing a promising model for the development of novel abrasion resistant materials. Here, we constructed de novo assembled transcripts from the radular tissue of C. stelleri that were used for transcriptome and proteome analysis. Transcriptomic analysis revealed that the top 20 most highly expressed transcripts in the non-mineralized teeth region include the transcripts encoding ferritin, while those in the mineralized teeth region contain a high proportion of mitochondrial respiratory chain proteins. Proteomic analysis identified 22 proteins that were specifically expressed in the mineralized cusp. These specific proteins include a novel protein that we term radular teeth matrix protein1 (RTMP1), globins, peroxidasins, antioxidant enzymes and a ferroxidase protein. This study reports the first de novo transcriptome assembly from C. stelleri, providing a broad overview of radular teeth mineralization. This new transcriptomic resource and the proteomic profiles of mineralized cusp are valuable for further investigation of the molecular mechanisms of radular teeth mineralization in chitons.

Published
2019

4. The Multiphasic Teeth of Chiton Articulatus, an Abrasion‐Resistant and Self‐Sharpening Tool for Hard Algae Collection.

Author

Montroni, Devis, Sarmiento, Ezra, Zhao, Ruoheng, Dasika, Phani Saketh, Connolly, John Michael, Wuhrer, Richard, Zhang, Yugang, Zhernenkov, Mikhail, Wang, Taifeng, Ramirez‐Santana, Brenda Paola, Sheppard, Leigh, Avila‐Poveda, Omar Hernando, Arakaki, Atsushi, Nemoto, Michiko, Zavattieri, Pablo, and Kisailus, David

Subjects
ORGANIC wastes, SOLID waste, MAGNETITE, BIOMINERALIZATION, TEETH, GOETHITE
Abstract

Chiton articulatus is a species of mollusk living in the tropical Pacific intertidal rocky shores of Mexico. This species feeds on solid waste organic sources, including hard crustose algae that grow on rocky substrates, by grazing on them with its radula, a flexible chitinous membrane lined with mineralized major lateral teeth. In this study, the composition, morphology, and resulting mechanics of the mature teeth of this species, which have yet to be examined, are revealed. The results show the presence of multiphasic mature teeth, each consisting of aligned hard magnetite nanoparticles on the leading edge of the tooth underneath which are magnetite lamellae, followed by goethite, lepidocrocite, and eventually hydroxyapatite near the trailing edge. This multiregional structure demonstrates a gradation in hardness as well as different microstructural features integrated with tough interfaces. The combination of these microstructural and phase arrangements results in an abrasion‐resistant tough structure with a self‐sharpening ability. The results of this work will help contribute to developing new bioinspired designs while also helping to understand the evolution and feeding habits of these intriguing invertebrates. [ABSTRACT FROM AUTHOR]

Published
2024
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12. Fibrous anisotropy and mineral gradients Within the radula stylus of chiton: Controlled stiffness and damage tolerance in a flexible biological composite

Author

Lee, Jung-Eun, primary, Connolloy, John, additional, Yang, Wen, additional, Freychet, Guillaume, additional, Wang, Taifeng, additional, Herrera, Steven A, additional, Murata, Satoshi, additional, Dasika, Phani Saketh, additional, Montroni, Devis, additional, Pohl, Anna, additional, Zhu, Chenhui, additional, Zhernenkov, Mikhail, additional, Wuhrer, Richard, additional, Sheppard, Leigh, additional, Nemoto, Michiko, additional, Arakaki, Atsushi, additional, Zavattieri, Pablo, additional, and Kisailus, David, additional

Published
2022
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14. Evaluation of the Geenius HIV 1/2 confirmatory assay for HIV-2 samples isolated in Japan

Author

Shigemi, Urara, primary, Yamamura, Yoshimi, additional, Matsuda, Masakazu, additional, Okazaki, Reiko, additional, Kubota, Mai, additional, Ibe, Shiro, additional, Nemoto, Michiko, additional, Maejima-Kitagawa, Masami, additional, Sukegawa, Sayaka, additional, Imahashi, Mayumi, additional, Kikuchi, Tadashi, additional, Sugiura, Wataru, additional, Iwatani, Yasumasa, additional, Hachiya, Atsuko, additional, and Yokomaku, Yoshiyuki, additional

Published
2022
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16. Nanoarchitected tough biological composites from assembled chitinous scaffolds

Author

Huang, Wei, Montroni, Devis, Wang, Taifeng, Murata, Satoshi, Arakaki, Atsushi, Nemoto, Michiko, Kisailus, David, Huang, Wei, Montroni, Devis, Wang, Taifeng, Murata, Satoshi, Arakaki, Atsushi, Nemoto, Michiko, and Kisailus, David

Abstract

ConspectusOver hundreds of millions of years, organisms have derived specific sets of traits in response to common selection pressures that serve as guideposts for optimal biological designs. A prime example is the evolution of toughened structures in disparate lineages within plants, invertebrates, and vertebrates. Extremely tough structures can function much like armor, battering rams, or reinforcements that enhance the ability of organisms to win competitions, find mates, acquire food, escape predation, and withstand high winds or turbulent flow. From an engineering perspective, biological solutions are intriguing because they must work in a multifunctional context. An organism rarely can be optimally designed for only one function or one environmental condition. Some of these natural systems have developed well-orchestrated strategies, exemplified in the biological tissues of numerous animal and plant species, to synthesize and construct materials from a limited selection of available starting materials. The resulting structures display multiscale architectures with incredible fidelity and often exhibit properties that are similar, and frequently superior, to mechanical properties exhibited by many engineered materials. These biological systems have accomplished this feat through the demonstrated ability to tune size, morphology, crystallinity, phase, and orientation of minerals under benign processing conditions (i.e., near-neutral pH, room temperature, etc.) by establishing controlled synthesis and hierarchical 3D assembly of nano- to microscaled building blocks. These systems utilize organic-inorganic interactions and carefully controlled microenvironments that enable kinetic control during the synthesis of inorganic structures. This controlled synthesis and assembly requires orchestration of mineral transport and nucleation. The underlying organic framework, often consisting of polysaccharides and polypeptides, in these composites is critical in the spatial

Published
2022

17. Fibrous anisotropy and mineral gradients within the radula stylus of chiton: Controlled stiffness and damage tolerance in a flexible biological composite.

Author

Lee, Jung-Eun, Connolly, John, Yang, Wen, Freychet, Guillaume, Wang, Taifeng, Herrera, Steven A, Murata, Satoshi, Dasika, Phani Saketh, Montroni, Devis, Pohl, Anna, Zhu, Chenhui, Zhernenkov, Mikhail, Wuhrer, Richard, Sheppard, Leigh, Nemoto, Michiko, Arakaki, Atsushi, Zavattieri, Pablo, and Kisailus, David

Subjects
BIOCOMPATIBILITY, MINERALS, ANISOTROPY, ENGINEERING design, SOFT robotics, FIBER orientation
Abstract

Over hundreds of millions of years, organisms have evolved architected structures via precise control over hierarchically assembled components, including the integration of dissimilar materials. One such example is found in the radula system of chitons, intertidal mollusks that feed on algae growing on the rock. Their radula consists of multiple rows of ultrahard teeth, each integrated with a foldable belt-like substrate via a stiff, yet flexible stylus, which is essential for efficient rasping during the feeding process. Here, we investigate the nano and micro-scale components and architectures as well as regional mechanical properties of the stylus, and their subsequent role during the rasping of Cryptochiton stelleri. Three important factors were determined to contribute to the regio-specific stiffness of the stylus: the presence of mineral components, highly oriented chitinous fibers, and a chemically cross-linked protein matrix. All these factors are varied throughout the stylus. There is a high mineral content on the trailing edge close to the tooth and a cross-linked matrix on the leading edge, both with orientational specific oriented chitin fibers that provide force transduction to the tooth. Conversely, there is a significant lack of mineral or cross-linked matrix in the proximal end as well as a low degree of fiber orientation, resulting in a flexible region that can accommodate torsion and flexure during rasping. Understanding the graded composite structure of the stylus and applying this unique design to various engineering fields such as soft robotics, biotechnology, and the medical industry, can inspire the production of high-performance materials. Graphical Abstract [ABSTRACT FROM AUTHOR]

Published
2023
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19. Mesocrystalline Ordering and Phase Transformation of Iron Oxide Biominerals in the Ultrahard Teeth of Cryptochiton stelleri

Author

Wang, Taifeng, primary, Huang, Wei, additional, Pham, Cong Huy, additional, Murata, Satoshi, additional, Herrera, Steven, additional, Kirchhofer, Nathan D., additional, Arkook, Bassim, additional, Stekovic, Dejan, additional, Itkis, Mikhail E., additional, Goldman, Nir, additional, Zepeda-Ruiz, Luis, additional, Freychet, Guillaume, additional, Zhernenkov, Mikhail, additional, Nemoto, Michiko, additional, Arakaki, Atsushi, additional, and Kisailus, David, additional

Published
2022
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23. Multiple mutations in RNA polymerase β-subunit gene (rpoB) in Streptomyces incarnatus NRRL8089 enhance production of antiviral antibiotic sinefungin: modeling rif cluster region by density functional theory

Author

Ogawa, Saori, primary, Shimidzu, Hitomi, additional, Fukuda, Koji, additional, Tsunekawa, Naoki, additional, Hirano, Toshiyuki, additional, Sato, Fumitoshi, additional, Yura, Kei, additional, Hasunuma, Tomohisa, additional, Ochi, Kozo, additional, Yamamoto, Michio, additional, Sakamoto, Wataru, additional, Hashimoto, Kentaro, additional, Ogata, Hiroyuki, additional, Kanao, Tadayoshi, additional, Nemoto, Michiko, additional, Inagaki, Kenji, additional, and Tamura, Takashi, additional

Published
2021
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24. Radular stylus of Cryptochiton stelleri: A multifunctional lightweight and flexible fiber-reinforced composite

Author

Pohl, Anna, primary, Herrera, Steven A., additional, Restrepo, David, additional, Negishi, Ryo, additional, Jung, Jae-Young, additional, Salinas, Chris, additional, Wuhrer, Richard, additional, Yoshino, Tomoko, additional, McKittrick, Joanna, additional, Arakaki, Atsushi, additional, Nemoto, Michiko, additional, Zavattieri, Pablo, additional, and Kisailus, David, additional

Published
2020
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26. Multiple mutations in RNA polymerase β-subunit gene (rpoB) in Streptomyces incarnatusNRRL8089 enhance production of antiviral antibiotic sinefungin: modeling rif cluster region by density functional theory

Author

Ogawa, Saori, Shimidzu, Hitomi, Fukuda, Koji, Tsunekawa, Naoki, Hirano, Toshiyuki, Sato, Fumitoshi, Yura, Kei, Hasunuma, Tomohisa, Ochi, Kozo, Yamamoto, Michio, Sakamoto, Wataru, Hashimoto, Kentaro, Ogata, Hiroyuki, Kanao, Tadayoshi, Nemoto, Michiko, Inagaki, Kenji, and Tamura, Takashi

Abstract

Streptomyces incarnatusNRRL8089 produces the antiviral, antifungal, antiprotozoal nucleoside antibiotic sinefungin. To enhance sinefungin production, multiple mutations were introduced to the rpoBgene encoding RNA polymerase (RNAP) β-subunit at the target residues, D447, S453, H457, and R460. Sparse regression analysis using elastic-net lasso-ridge penalties on previously reported H457X mutations identified a numeric parameter set, which suggested that H457R/Y/F may cause production enhancement. H457R/R460C mutation successfully enhanced the sinefungin production by 3-fold, while other groups of mutations, such as D447G/R460C or D447G/H457Y, made moderate or even negative effects. To identify why the rif cluster residues have diverse effects on sinefungin production, an RNAP/DNA/mRNA complex model was constructed by homology modeling and molecular dynamics simulation. The 4 residues were located near the mRNA strand. Density functional theory–based calculation suggested that D447, H457, and R460 are in direct contact with ribonucleotide, and partially positive charges are induced by negatively charged chain of mRNA.Graphical AbstractMultiple mutations introduced to RNA polymerase enhanced sinefungin production. RNAP/DNA/mRNA complex model was constructed and DFT calculation estimated interaction between rif-cluster residues and mRNA.

Published
2021
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27. Compound heterozygous TYK2 mutations underlie primary immunodeficiency with T-cell lymphopenia

Author

Nemoto, Michiko, primary, Hattori, Hiroyoshi, additional, Maeda, Naoko, additional, Akita, Nobuhiro, additional, Muramatsu, Hideki, additional, Moritani, Suzuko, additional, Kawasaki, Tomonori, additional, Maejima, Masami, additional, Ode, Hirotaka, additional, Hachiya, Atsuko, additional, Sugiura, Wataru, additional, Yokomaku, Yoshiyuki, additional, Horibe, Keizo, additional, and Iwatani, Yasumasa, additional

Published
2018
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30. Gene cloning, recombinant expression, purification and characterization of l-methionine decarboxylase fromStreptomycessp. 590

Author

Hayashi, Masaya, primary, Okada, Akane, additional, Yamamoto, Kumiko, additional, Okugochi, Tomomi, additional, Kusaka, Chika, additional, Kudou, Daizou, additional, Nemoto, Michiko, additional, Inagaki, Junko, additional, Hirose, Yuu, additional, Okajima, Toshihide, additional, Tamura, Takashi, additional, Soda, Kenji, additional, and Inagaki, Kenji, additional

Published
2016
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34. Structural Insights into HIV-1 Vif-APOBEC3F Interaction

Author

Nakashima, Masaaki, primary, Ode, Hirotaka, additional, Kawamura, Takashi, additional, Kitamura, Shingo, additional, Naganawa, Yuriko, additional, Awazu, Hiroaki, additional, Tsuzuki, Shinya, additional, Matsuoka, Kazuhiro, additional, Nemoto, Michiko, additional, Hachiya, Atsuko, additional, Sugiura, Wataru, additional, Yokomaku, Yoshiyuki, additional, Watanabe, Nobuhisa, additional, and Iwatani, Yasumasa, additional

Published
2016
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39. Biomineralization: Phase Transformations and Structural Developments in the Radular Teeth of Cryptochiton Stelleri (Adv. Funct. Mater. 23/2013)

Author

Wang, Qianqian, primary, Nemoto, Michiko, additional, Li, Dongsheng, additional, Weaver, James C., additional, Weden, Brian, additional, Stegemeier, John, additional, Bozhilov, Krassimir N., additional, Wood, Leslie R., additional, Milliron, Garrett W., additional, Kim, Christopher S., additional, DiMasi, Elaine, additional, and Kisailus, David, additional

Published
2013
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40. Phase Transformations and Structural Developments in the Radular Teeth ofCryptochiton Stelleri

Author

Wang, Qianqian, primary, Nemoto, Michiko, additional, Li, Dongsheng, additional, Weaver, James C., additional, Weden, Brian, additional, Stegemeier, John, additional, Bozhilov, Krassimir N., additional, Wood, Leslie R., additional, Milliron, Garrett W., additional, Kim, Christopher S., additional, DiMasi, Elaine, additional, and Kisailus, David, additional

Published
2013
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49. Identification and characterization of the zosAgene involved in copper uptake in Bacillus subtilis168

Author

Fukuhara, Takahiro, Kobayashi, Kazuo, Kanayama, Yousuke, Enomoto, Shu-ichi, Kondo, Taeko, Tsunekawa, Naoki, Nemoto, Michiko, Ogasawara, Naotake, Inagaki, Kenji, and Tamura, Takashi

Abstract

dl-Penicillamine, a copper-specific metal chelator, remarkably suppressed the growth of Bacillus subtilis168 when added to a synthetic medium under Cu2+limitation. DNA microarray and screening of 2,602 knockout mutants showed that the zosAgene was de-repressed in the presence of 0.1% dl-penicillamine, and that the zosAmutant was sensitive to dl-penicillamine medium. The zosAmutant delayed the growth under Cu-limitation even without the chelator, and the sensitivity to dl-penicillamine was reversed by induction using 0.3 mM IPTG and the Pspacpromoter inserted directly upstream of the zosAgene. Furthermore, the zosAmutant showed elevated tolerance of excessive Cu2+but not of excessive Zn2+added to LB and synthetic media. Homology modeling of the ZosA protein suggested that the protein can fold itself into essential domains for constituting a metal transporting ATPase. Our study suggests that zosAis a candidate gene involved in copper uptake.

Published
2016
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50. Phase Transformations and Structural Developments in the Radular Teeth of Cryptochiton Stelleri.

Author

Wang, Qianqian, Nemoto, Michiko, Li, Dongsheng, Weaver, James C., Weden, Brian, Stegemeier, John, Bozhilov, Krassimir N., Wood, Leslie R., Milliron, Garrett W., Kim, Christopher S., DiMasi, Elaine, and Kisailus, David

Subjects
*BIOMINERALIZATION, *GIANT Pacific chiton, *MAGNETITE crystals, *TEETH, *PHASE transitions
Abstract

During mineralization, the hard outer magnetite-containing shell of the radular teeth of Cryptochiton stelleri undergoes four distinct stages of structural and phase transformations: (i) the formation of a crystalline α-chitin organic matrix that forms the structural framework of the non-mineralized teeth, (ii) the templated synthesis of ferrihydrite crystal aggregates along these organic fibers, (iii) subsequent solid state phase transformation from ferrihydrite to magnetite, and (iv) progressive magnetite crystal growth to form continuous parallel rods within the mature teeth. The underlying α-chitin organic matrix appears to influence magnetite crystal aggregate density and the diameter and curvature of the resulting rods, both of which likely play critical roles in determining the local mechanical properties of the mature radular teeth. [ABSTRACT FROM AUTHOR]

Published
2013
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