title: Electron diffraction and high-resolution imaging on highly-crystalline β-chitin microfibril.
abstract: The ultrastructure of β-chitin microfibrils from a centric diatom, Thalassiosira, and a tubeworm, Lamellibrachia, was studied using electron diffraction and high-resolution electron microscopy. Electron microdiffraction diagrams corresponding to each projection of the β-chitin crystals were obtained, and all the data support the structure model of anhydrous β-chitin crystals proposed by X-ray diffraction experiments. From high-resolution electron microscopy on ultrathin sections, the cross-sectional shapes of the microfibrils from Thalassiosira and Lamellibrachia were observed as a rectangular and parallelogram, respectively. The lattice fringes corresponding to the (010) plane of anhydrous β-chitin crystals were clearly observed in both cross-sections. Based on these observations, we have constructed a molecular packing model for β-chitin microfibrils.
authors.affiliation: Department of Biomaterials Science, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113-8657, Japan.
authors.forename: Yu
authors.initials: Y
authors.lastname: Ogawa
authors.forename: Satoshi
authors.initials: S
authors.lastname: Kimura
authors.forename: Masahisa
authors.initials: M
authors.lastname: Wada
mesh_terms: D000818:Animals; D002236:Carbohydrate Conformation; D002686:Chitin / Q000378:metabolism / Q000648:ultrastructure*; D003460:Crystallization; D020894:Microfibrils / Q000378:metabolism / Q000648:ultrastructure*; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D008867:Microtomy; D008958:Models, Molecular; D011077:Polychaeta / Q000378:metabolism
chemical_list: D002686:Chitin