Updated on 2022/01/24


FUJII, Kazunori
Faculty of Science and Engineering, School of Advanced Science and Engineering
Job title
Research Associate


  • 修士



  • Lowering the culture temperature corrects collagen abnormalities caused by HSP47 gene knockout.

    Kazunori K Fujii, Yuki Taga, Takayuki Sakai, Shinya Ito, Shunji Hattori, Kazuhiro Nagata, Takaki Koide

    Scientific reports   9 ( 1 ) 17433 - 17433  2019.11  [Refereed]  [International journal]

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    Heat shock protein 47 (HSP47) is an endoplasmic reticulum (ER)-resident molecular chaperone that specifically recognizes triple helical portions of procollagens. The chaperone function of HSP47 is indispensable in mammals, and hsp47-null mice show an embryonic lethal phenotype accompanied by severe abnormalities in collagen-based tissue structures. Two leading hypotheses are currently accepted for the molecular function of HSP47 as a procollagen-specific chaperone. One is facilitation of procollagen folding by stabilizing thermally unstable triple helical folding intermediates, and the other is inhibition of procollagen aggregation or lateral association in the ER. The aim of this study was to elucidate the functional essence of this unique chaperone using fibroblasts established from hsp47-/- mouse embryos. When the cells were cultured at 37 °C, various defects in procollagen biosynthesis were observed, such as accumulation in the ER, over-modifications including prolyl hydroxylation, lysyl hydroxylation, and further glycosylation, and unusual secretion of type I collagen homotrimer. All defects were corrected by culturing the cells at a lower temperature of 33 °C. These results indicated that lowering the culture temperature compensated for the loss of HSP47. This study elucidated that HSP47 stabilizes the elongating triple helix of procollagens, which is otherwise unstable at the body temperature of mammals.

    DOI PubMed

  • Structural optimization of cyclic peptides that efficiently detect denatured collagen.

    Takita KK, Fujii KK, Ishii K, Koide T

    Organic & biomolecular chemistry   17 ( 31 ) 7380 - 7387  2019.08  [Refereed]

    DOI PubMed

  • Cyclic Peptides for Efficient Detection of Collagen

    Koh K. Takita, Kazunori K. Fujii, Tetsuya Kadonosono, Ryo Masuda, Takaki Koide

    ChemBioChem   19 ( 15 ) 1613 - 1617  2018.08  [Refereed]

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    © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim We report here a new class of collagen-binding peptides, cyclic collagen-mimetic peptides (cCMPs), that efficiently hybridize with the triple-helix-forming portions of collagen. cCMPs are composed of two parallel collagen-like (Xaa-Yaa-Gly)n strands with both termini tethered by covalent linkages. Enzyme-linked immunosorbent assays and western blotting analysis showed that cCMPs exhibit more potent affinity toward collagen than reported collagen-binding peptides and can specifically detect different collagen polypeptides in a mixture of proteins. Collagen secreted from cultured cells was detected by confocal microscopy with fluorescein-labeled cCMP. The cCMP is also shown to detect sensitively folding intermediates in the endoplasmic reticulum, something that was difficult to visualize with conventional collagen detectors. Molecular-dynamics simulations suggested that a cCMP forms a more stably hybridized product than its single-chain counterpart; this could explain why cCMP has higher affinity toward denatured collagen. These results indicate the usefulness of cCMPs as tools for detecting denatured collagen.

    DOI PubMed

Specific Research

  • 環境温度が魚類コラーゲンに与える影響

    2020   小出 隆規

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