Lattice images from ultrathin sections of cellulose microfibrils in the cell wall of Valonia macrophysa K�tz.

Sugiyama, Junji; Harada, Hiroshi; Fujiyoshi, Yoshinori; Uyeda, Natsu

doi:10.1007/bf00397343

Cited by 138 publications

(66 citation statements)

References 16 publications

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“…This model was later confirmed by negative staining and tilt experiments (Goto et al 1973), by diffraction contrast and microdiffraction analysis (Revol 1982, Revol andGoring 1983) as well as by direct visualization of crystal lattice planes (Sugiyama et al 1985) of cellulose in the cell wall of Valonia spp., green marine algae. A similar model is proposed for cellulose ribbons with uniplanar orientation of 0.60 nm lattice planes, for instance bacterial cellulose microfibrils.…”

Section: Introductionmentioning

confidence: 63%

High-resolution electron microscopy on ultrathin sections of cellulose microfibrils generated by glomerulocytes in Polyzoa vesiculiphora

et al. 1998

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Summary. Glomerulocyte cellulosic bundles of Polyzoa vesiculiphora were investigated by microdiffraction and high-resolution electron microscopy. In each bundle, hundreds of cellulose microfibrils, having a rectangular cross-sectional shape, are packed regularly with their 0.6 nm lattice planes parallel to each other. Lattice images reveal that the 0.6 nm plane is parallel to the longer edge of the cross section which is similar to the lattice organization of cellulose with a squarish cross section in Valonia spp. More interestingly, all the microfibrils in a bundle have the same directionality of crystallographic c-axis, which suggests that the biosynthesis of the microfibrils within particular bundle occurs unidirectionally.

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Section: Introductionmentioning

confidence: 63%

High-resolution electron microscopy on ultrathin sections of cellulose microfibrils generated by glomerulocytes in Polyzoa vesiculiphora

et al. 1998

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“…Because one single microfibril is virtually a single crystal (16,17), one can assign the c direction from elementary crystallographic considerations as schematically represented in Fig. 3.…”

Section: Resultsmentioning

confidence: 99%

Parallel-up structure evidences the molecular directionality during biosynthesis of bacterial cellulose

Koyama

Helbert

Imai

et al. 1997

Proc. Natl. Acad. Sci. U.S.A.

266

171

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The ''parallel-up'' packing in cellulose I ␣ and I ␤ unit cells was experimentally demonstrated by a combination of direct-staining the reducing ends of cellulose chains and microdiffraction-tilting electron crystallographic analysis. Microdiffraction investigation of nascent bacterial cellulose microfibrils showed that the reducing end of the growing cellulose chains points away from the bacterium, and this provides direct evidence that polymerization by the cellulose synthase takes place at the nonreducing end of the growing cellulose chains. This mechanism is likely to be valid also for a number of processive glycosyltransferases such as chitin synthases, hyaluronan synthases, and proteins involved in the synthesis of nodulation factor backbones.The polarity of cellulose chains in a microfibril was debated for decades before two groups independently proved the parallel packing by electron microscopic methods. One involved the silver-labeling of the reducing ends of microfibrils (1), while the other was based on the unidirectional degradation of cellulose microfibrils by a cellobiohydrolase (2). In both studies, the cellulose from Valonia was used because of the high crystallinity and large lateral dimension of the microfibrils. Later, the silver-labeling technique was applied to bacterial cellulose and showed the same parallel packing (3). These microscopic analyses confirmed earlier crystallographic proposals that the most probable mode of packing in the unit cell was parallel (4-6).The current knowledge on the crystal structure of cellulose is that the native cellulose is a composite of two distinct crystalline phases called I ␣ and I ␤ (7, 8) corresponding to triclinic and monoclinic unit cells, respectively (9). The existence of the I ␣ and I ␤ structures within a microfibril is another confirmation of the parallel packing, because the triclinic unit accepts only one single chain in a unit cell. Furthermore, the fact that I ␣ and I ␤ coexist in a microfibril suggests that the chains in I ␣ -rich as well as in I ␤ -rich cellulose are parallel. Although the parallel packing of the chains in a cellulose microfibril or a unit cell is now firmly established, the molecular directionality of the chains with respect to the unit cells is not known.Directionality of cellulose chains in a unit cell is frequently defined according to Gardner and Blackwell (4). There are two types of parallel packing, namely, parallel up and parallel down. The parallel-up structure implies that the z coordinate of the O5 atom is greater than that of C5. Two parallel models with opposite molecular directionality thus have been proposed (4) and critically evaluated (10). Molecular dynamics studies recently have suggested that the parallel-up structure was most probable for both cellulose I ␣ and I ␤ (11).The first aim of the current research was to determine experimentally the chain directionality in a unit cell by using electron crystallography in conjunction with the reducing end staining technique. Once established, the deter...

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“…At the ultrastructural level, this statement is supported by recording of high-resolution details of large highly crystalline microfibrils such as those of Valonia, tunicin, Micrasterias etc. Indeed, the analysis of their cross-sections by electron diffraction and diffraction contrast electron microscopy, including lattice imaging, clearly indicates that their surface corresponds to either the (1 1 0) and (1 -1 0) planes of the monoclinic cellulose Ib lattice or the (1 0 0) and (0 1 0) of its triclinic Ia counterpart (Sugiyama et al 1991), which are rich in hydrophilic OH moieties (Sugiyama et al 1985;Revol 1982;Helbert et al 1998;Kim et al 1996). Observations of Valonia surface at near atomic resolution by AFM is in agreement with the TEM results as they definitely show organized arrays of surface hydroxymethyl groups within the Ia phase of Valonia cellulose (Baker et al 1997(Baker et al , 2000.…”

Section: Introductionmentioning

confidence: 99%

“…In theory, this (1 1 0) surface should be negligible in cellulose, being reduced to an acute corner consisting of only one chain if the Valonia microfibrils had a perfect squarish section delineated by the hydrophilic (1 0 0) and (0 1 0) triclinic surfaces. In fact the ultrastructural observations on cross-sections have revealed that the corners of the Valonia microfibrils were frequently blunt (Sugiyama et al 1985;Lehtiö et al 2003;Xu et al 2009;Mazeau 2011) and thus the occurrence of a significant secondary surface such as that of the hydrophobic triclinic (1 1 0) face appears to be far from negligible. This occurrence explains why it is a hydrophobic type of an interaction that is likely to account for the affinity of cellulase for crystalline cellulose.…”

Section: Introductionmentioning

confidence: 99%

Modelling of Congo red adsorption on the hydrophobic surface of cellulose using molecular dynamics

Mazeau

Wyszomirski

2012

Cellulose

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This study describes the interaction between crystalline cellulose and the direct dye Congo red (CR) using molecular dynamics simulations. A model of a microfibril corner of cellulose Ib, exposing one hydrophobic (1 0 0) and the two hydrophilic (1 1 0) and (1 -1 0) surfaces was built. The energetic and geometric features of the dye adsorption were investigated at different temperatures following different initial positions of the CR. The relative positions and orientations of the CR with respect to the cellulose surface were unambiguously characterized using three translation (shift, slide, and rise) and three rotation (roll, tilt, and twist) parameters. Changes of twist and roll parameters showed that there was a tendency for the once adsorbed dye molecules, to become more planar and parallel to the cellulose surface. Several stable adsorption sites, translated laterally with respect to one another were obtained and adsorbed CR molecules were laid with their long axis either parallel or inclined by 50°with respect to the cellulose chain axis. Both vacuum and explicit water environments were considered. In this latter case, there was an increase in the energy of interaction between CR and cellulose and the adsorbed dye molecule behaved more rigidly than in vacuum case.

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Lattice images from ultrathin sections of cellulose microfibrils in the cell wall of Valonia macrophysa K�tz.

Cited by 138 publications

References 16 publications

High-resolution electron microscopy on ultrathin sections of cellulose microfibrils generated by glomerulocytes in Polyzoa vesiculiphora

High-resolution electron microscopy on ultrathin sections of cellulose microfibrils generated by glomerulocytes in Polyzoa vesiculiphora

Parallel-up structure evidences the molecular directionality during biosynthesis of bacterial cellulose

Modelling of Congo red adsorption on the hydrophobic surface of cellulose using molecular dynamics

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