scholarly journals Molecular directionality in crystalline β-chitin: hydrolysis by chitinases A and B from Serratia marcescens 2170

2005 ◽  
Vol 388 (3) ◽  
pp. 851-856 ◽  
Author(s):  
Eva-Lena HULT ◽  
Fuminori KATOUNO ◽  
Taku UCHIYAMA ◽  
Takeshi WATANABE ◽  
Junji SUGIYAMA
Keyword(s):  
Serratia Marcescens ◽  
Reducing Sugars ◽  
Three Dimensional ◽  
Combined Analysis ◽  
Synergistic Interactions ◽  
Chitin Hydrolysis ◽  
Gold Labelling ◽  
Labelling Method ◽  
Crystallographic Axes ◽  
Simultaneous Degradation

β-Chitin microfibrils were treated with ChiA and ChiB (chitinases A and B respectively) from Serratia marcescens 2170. The β-chitin microfibrils were shortened, and the tips appeared narrowed and sharpened at both ends, after either consecutive or simultaneous degradation by ChiA and ChiB. Increased production of reducing sugars by simultaneous degradation (by ChiA and ChiB) of β-chitin, but not of glycol chitin, suggests synergistic interactions between the two enzymes. A combined analysis using the tilt microdiffraction method to determine the crystallographic axes, together with the biotin–streptavidin–gold-labelling method specific to the reducing ends, was used to investigate the polarity of the degraded β-chitin microcrystals. The digestion of the β-chitin fibrils by ChiA occurred from the reducing end to the nonreducing end, whereas digestion by ChiB occurred from the non-reducing end to the reducing end. The results are in agreement with the previously determined three-dimensional structures of these enzymes.

The RNA content of the nucleolus and nucleolus-like inclusions in the anther of Lilium estimated by an improved RNase-gold labelling method

1989 ◽  
Vol 94 (4) ◽  
pp. 675-683
Author(s):  
S. SATO ◽  
C. WILLSON ◽  
H. G. DICKINSON
Keyword(s):  
Electric Discharge ◽  
Condensed Chromatin ◽  
Tetrad Stage ◽  
Dense Bodies ◽  
Rna Content ◽  
Predominant Type ◽  
Tapetal Cells ◽  
Gold Labelling ◽  
Labelling Method ◽  
Specific Labelling

Using RNase-gold labelling a comparative estimation has been made of the RNA content of the nucleoli and nucleolus-like inclusions in anther cells of Lilium henryi Thunb. Pretreatment with glow electric discharge prior to application of the RNase-gold labelling remarkably lowered the level of nonspecific adsorption and allowed specific labelling of RNA-containing structures. In the tapetal cells, the nucleoli, the perichromatin material and the dense bodies labelled heavily, but both the interchromatin region and the condensed chromatin did not bind the label. The nucleolus-like inclusions, which were found in the nucleoplasm of meiotic cells at the tetrad stage, and were termed ‘nuclear nucleolus-like bodies (NLBs)’ in the present study, also showed a high response compared with both the loosened and the condensed chromatin; this labelling was some 60% of that observed over the nucleoli of somatic cells. Another type of nuclear NLB was differentiated from the predominant type of NLB by a conspicuous electron opacity, reduced size, and strong labelling with the RNasegold complex, suggesting that some nuclear NLBs may be highly condensed. The labelling over the cytoplasmic nucleoloids (nucleolus-like inclusions found in the cytoplasm) was only 50 % of that over the nuclear NLBs, although both are similar in ultrastructural texture.

scholarly journals Polyurethane/Red Mud Composites with Flexibility, Stretchability, and Flame Retardancy for Grouting

Polymers ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 906 ◽  
Author(s):  
Chunjing Zhang ◽  
Bo Shuai ◽  
Xuefeng Zhang ◽  
Xinxin Hu ◽  
Hui Zhang ◽  
...  
Keyword(s):  
Polyethylene Glycol ◽  
Flame Retardancy ◽  
Red Mud ◽  
Three Dimensional ◽  
Engineering Application ◽  
Synergistic Interactions ◽  
Grouting Material ◽  
Dimensional Network ◽  
Grouting Materials ◽  
Inorganic Composite

Flexibility, stretchability, and flame retardancy are of ever increasing importance in constructing grouting materials. Herein, a simple and effective strategy to make organic-inorganic composite grouting material in a “flexible, stretchable, and flame retardant” way was based on the excellent synergistic interactions among polyurethane prepolymer, red mud, polyethylene glycol, and trimethylolpropane. The resultant polyurethane/red mud composite grouting material with three-dimensional network structure presented a favorable flexibility, desirable compressive strength of 29.2 MPa at 50% compression state, and a good elongation at 15.1%. The grouting material was mainly composed of amorphous polyurethane and crystalline red mud, and its probable formation mechanism was reaction of prepolymer with H2O, polyethylene glycol and trimethylolpropane under vigorous stirring in the presence of catalyst. Furthermore, the grouting material possessed favorable thermal stability, flame retardancy and repairment performance for roadway cracks. This work may open a simple and convenient avenue for the massive engineering application of red mud and preparation of flexible organic-inorganic hybrid grouting material.

An Executable Notation, With Illustrations From Elementary Crystallography

1994 ◽  
Author(s):  
Donald B. Mclntyre
Keyword(s):  
Plate Tectonics ◽  
Periodic Structures ◽  
Dimensional Space ◽  
Reciprocal Lattice ◽  
Three Dimensional ◽  
Cubic Symmetry ◽  
Multiple Data ◽  
Special Cases ◽  
Unit Cells ◽  
Crystallographic Axes

Elementary crystallography is an ideal context for introducing students to mathematical geology. Students meet crystallography early because rocks are made of crystalline minerals. Moreover, morphological crystallography is largely the study of lines and planes in real three-dimensional space, and visualizing the relationships is excellent training for other aspects of geology; many algorithms learned in crystallography (e.g., rotation of arrays) apply also to structural geology and plate tectonics. Sets of lines and planes should be treated as entities, and crystallography is an ideal environment for introducing what Sylvester (1884) called "Universal Algebra or the Algebra of multiple quantity." In modern terminology, we need SIMD (Single Instruction, Multiple Data) or even MIMD. This approach, initiated by W.H. Bond in 1946, dispels the mysticism unnecessarily associated with Miller indices and the reciprocal lattice; edges and face-normals are vectors in the same space. The growth of mathematical notation has been haphazard, new symbols often being introduced before the full significance of the functions they represent had been understood (Cajori, 1951; Mclntyre, 1991b). Iverson introduced a consistent notation in 1960 (e.g., Iverson 1960, 1962, 1980). His language, greatly extended in the executable form called J (Iverson, 1993), is used here. For information on its availability as shareware, see the Appendix. Publications suitable as tutorials in , J are available (e.g., Iverson. 1991; Mclntyre, 1991 a, b; 1992a,b,c; 1993). Crystals are periodic structures consisting of unit cells (parallelepipeds) repeated by translation along axes parallel to the cell edges. These edges define the crystallographic axes. In a crystal of cubic symmetry they are orthogonal and equal in length (Cartesian). Those of a triclinic crystal, on the other hand, are unequal in length and not at right angles. The triclinic system is the general case; others are special cases. The formal description of a crystal gives prominent place to the lengths of the axes (a, b, and c) and the interaxial angles ( α, β, and γ). A canonical form groups these values into a 2 x 3 table (matrix), the first row being the lengths and the second the angles.

Growth and structural and physical properties of diisopropylammonium bromide molecular single crystals

2016 ◽  
Vol 49 (6) ◽  
pp. 2053-2062 ◽  
Author(s):  
Harsh Yadav ◽  
Nidhi Sinha ◽  
Sahil Goel ◽  
Abid Hussain ◽  
Binay Kumar
Keyword(s):  
Single Crystals ◽  
Grown Crystal ◽  
Three Dimensional ◽  
Solution Technique ◽  
X Ray Diffraction ◽  
X Ray ◽  
Dielectric Constant And Loss ◽  
Vis Spectroscopy ◽  
Direct Band ◽  
Crystallographic Axes

Large single crystals of the promising molecular organic ferroelectric diisopropylammonium bromide (DIPAB) have been grown by the solution technique. A structural study was performed using single-crystal X-ray diffraction analysis. The twin element of a selected DIPAB crystal was identified by a morphological study. Intermolecular interactions present in the grown crystal were explored by Hirshfeld surface (three-dimensional) and fingerprint plot (two-dimensional) studies. In UV–vis spectroscopy, the DIPAB crystal has shown high transparency with a wide direct band gap of 5.65 eV. In the photoluminescence spectrum, sharp UV and blue emissions were observed at 370, 392, 417 and 432 nm. The electrical properties were investigated by measuring the dielectric constant (∊) and loss (tanδ) of the grown crystal. The DIPAB crystal exhibits a promising piezoelectric charge coefficient (d33) value of 18 pC N−1, which makes it suitable for transducer applications. A high ferroelectric Curie temperature (Tc≃ 425 K) with high remnant polarization (20.52 µC cm−2) and high coercive field (12.25 kV cm−1) were observed in the as-grown crystal. Vickers microhardness analysis shows that the value of Meyer's index (n= 7.27) belongs to the soft material range, which was also confirmed by void analysis along three crystallographic axes. It is shown that the DIPAB crystal has potential for optical, ferroelectric and piezoelectric applications.

MoS2 nanosheet-coated CoS2 nanowire arrays on carbon cloth as three-dimensional electrodes for efficient electrocatalytic hydrogen evolution

2015 ◽  
Vol 3 (45) ◽  
pp. 22886-22891 ◽  
Author(s):  
Jilin Huang ◽  
Dongman Hou ◽  
Yucheng Zhou ◽  
Weijia Zhou ◽  
Guoqiang Li ◽  
...  
Keyword(s):  
Hydrogen Evolution ◽  
Three Dimensional ◽  
Nanowire Arrays ◽  
Carbon Cloth ◽  
Synergistic Interactions ◽  
Mos2 Nanosheet

MoS2 nanosheet-coated CoS2 nanowire arrays supported on carbon cloth exhibited excellent HER activity with an overpotential of −87 mV (vs. RHE) at 10 mA cm−2 due to the synergistic interactions between MoS2 and CoS2.

scholarly journals Uptake of N,N′-Diacetylchitobiose [(GlcNAc)2] via the Phosphotransferase System Is Essential for Chitinase Production by Serratia marcescens 2170

2003 ◽  
Vol 185 (6) ◽  
pp. 1776-1782 ◽  
Author(s):  
Taku Uchiyama ◽  
Ryousuke Kaneko ◽  
Junko Yamaguchi ◽  
Akane Inoue ◽  
Takahiro Yanagida ◽  
...  
Keyword(s):  
Serratia Marcescens ◽  
Carbon Sources ◽  
Major Product ◽  
Essential Factor ◽  
Specific Enzyme ◽  
Phosphotransferase System ◽  
Major Pathway ◽  
Chitin Hydrolysis ◽  
Chitinase Production ◽  
Chitin Binding Protein

ABSTRACT The chiR gene of Serratia marcescens 2170, encoding a LysR-type transcriptional activator, was identified previously as an essential factor for expression of chitinases and a chitin-binding protein, CBP21. To identify other genes that are essential for chitinase production, transposon mutagenesis with mini-Tn5Km1 was carried out, and 25 mutants that were unable to produce chitinases and CBP21 were obtained. Analysis of the mutated gene of one of the mutants, N22, revealed the presence of a pts operon in this bacterium, and a mutation was found in ptsI in the operon. In addition to its inability to produce chitinase, N22 did not grow well on N-acetyl-d-glucosamine (GlcNAc), (GlcNAc)2, and some other carbon sources, most of which were phosphotransferase system (PTS) sugars. Thus, the inability to produce chitinase was assumed to be caused by the defect in uptake of (GlcNAc)2 via the PTS, considering that (GlcNAc)2 is the minimal substrate for chitinase induction and the major product of chitin hydrolysis by chitinases of this bacterium. To confirm this assumption, the chb operon, encoding the (GlcNAc)2-specific enzyme II permease, was cloned by reference to its Escherichia coli counterpart, and the Serratia chb operon was shown to comprise chbB, chbC, bglA, chbR, and chbG. Disruption of chbC drastically reduced production of chitinases and CBP21 and impaired growth on colloidal chitin. These results indicate that uptake of (GlcNAc)2 is mediated by the PTS and that the (GlcNAc)2-specific enzyme II permease constitutes its major pathway. Since (GlcNAc)2 uptake is essential for induction of chitinases and CBP21 production, (GlcNAc)2 appears to be the key molecule in recognition and utilization of chitin by S. marcescens.

scholarly journals Activities of the Serratia marcescens Heme Receptor HasR and Isolated Plug and β-Barrel Domains: the β-Barrel Forms a Heme-Specific Channel

2005 ◽  
Vol 187 (13) ◽  
pp. 4637-4645 ◽  
Author(s):  
Sylvie Létoffé ◽  
Karine Wecker ◽  
Muriel Delepierre ◽  
Philippe Delepelaire ◽  
Cécile Wandersman
Keyword(s):  
Serratia Marcescens ◽  
Outer Membrane ◽  
Three Dimensional ◽  
Membrane Receptors ◽  
Outer Membrane Receptor ◽  
Heme Uptake ◽  
Amino Terminal ◽  
Exogenous Compounds

ABSTRACT The Serratia marcescens hemophore-specific outer membrane receptor HasR is a member of the TonB-dependent family of autoregulated receptors. It can transport either heme itself or heme bound to the hemophore HasA. On the basis of sequence and functional similarities with other TonB-dependent outer membrane receptors whose three-dimensional structures have been determined, a HasR structure model was proposed. The mature HasR protein comprises a 99-residue amino-terminal extension necessary for hasR transcription, followed by a plug domain of 139 amino acids and a β-barrel domain inserted in the outer membrane, the lumen of which is closed by the plug. This model was used to generate hasR deletions encoding HasR proteins with the native signal peptides but lacking either the N-terminal regulatory extension or encoding the plug or the β-barrel alone. The protein lacking the N-terminal extension, HasR Δ11-91, was incorporated in the outer membrane and was fully functional for active uptake of free and hemophore-bound heme. The HasR β-barrel, Δ11-192, was also incorporated in the outer membrane and bound the hemophore but expressed no active heme transport properties. The HasR plug remained in the periplasm. Coexpression of the plug and the β-barrel allowed partial plug insertion in the outer membrane, demonstrating that these two HasR domains interact in vivo. The β-barrel and the plug also interact in vitro. Nevertheless, the two domains did not complement each other to reconstitute an active TonB-dependent receptor for free or hemophore-bound heme uptake. Production of the β-barrel alone selectively increased passive diffusion of heme but not of other exogenous compounds. A mutation at histidine 603, which is required for heme uptake through the wild-type receptor, abolished heme diffusion, showing that HasR Δ11-192 forms a specific heme channel.

Varying degrees of running incline: Implications for chronic injury aetiology and rehabilitation

2014 ◽  
Vol 10 (4) ◽  
pp. 207-214 ◽  
Author(s):  
J. Sinclair ◽  
A. Greenhalgh ◽  
P.J. Taylor ◽  
I. Bentley
Keyword(s):  
Lower Extremity ◽  
Internal Rotation ◽  
Repeated Measures ◽  
Three Dimensional ◽  
Treadmill Running ◽  
Clinical Perspective ◽  
Chronic Injury ◽  
Combined Analysis ◽  
Tibial Internal Rotation ◽  
Tibial Acceleration

There has yet to be a combined analysis of the kinetics and three-dimensional kinematics of running at various degrees of inclination. The aim of the current study was to investigate the influence of treadmill running at various inclines (flat, 5, 10 and 15 degrees) on three-dimensional kinematics of the lower extremities and accelerations measured at the tibia. Ten male participants ran at 4.0 m/s at the four different inclinations. Three-dimensional lower extremity kinematics and tibial accelerations were quantified and contrasted using repeated measures ANOVA's. Tibial acceleration parameters were reduced significantly as a function of running incline, whilst tibial internal rotation was significant greater at 15° compared to flat. This study confirms that differences in both kinetics and kinematics are mediated through alterations in running inclination. From a clinical perspective, those who are susceptible/ recovering from injury may wish to utilise an incline in their training.

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