Relations between Structure and Function in Cytoplasmic Membrane Vesicles Isolated from an Escherichia coli Fatty-Acid Auxotroph. High-Angle X-Ray Diffraction, Freeze-Etch Electron Microscopy and Transport Studies

IntroductionAfter a long period of anticipation,1 the last two years have witnessed the first high-resolution x-ray structures of fragments from fibrinogen and fibrin.2-7 The results confirmed many aspects of fibrinogen structure and function that had previously been inferred from electron microscopy and biochemistry and revealed some unexpected features. Several matters have remained stubbornly unsettled, however, and much more work remains to be done. Here, we review several of the most significant findings that have accompanied the new x-ray structures and discuss some of the problems of the fibrinogen-fibrin conversion that remain unresolved. * Abbreviations: GPR—Gly-Pro-Arg-derivatives; GPRPam—Gly-Pro-Arg-Pro-amide; GHRPam—Gly-His-Arg-Pro-amide

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Feeding Structures and their Functions in Adult and Preadult Tigriopus Californicus (Copepoda: Harpacticoida)

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315400041552 ◽

1998 ◽

Vol 78 (2) ◽

pp. 451-466 ◽

Cited By ~ 8

Author(s):

A.G. Lewis ◽

L. Chatters ◽

M. Raudsepp

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Structure And Function ◽

Energy Dispersive ◽

Tigriopus Californicus ◽

X Ray ◽

Faecal Pellets ◽

Spinous Processes ◽

And Function ◽

Scanning Electron

Tigriopus californicus uses several appendages and processes in the collection and manipulation of food. Their structure and function appear to enable the species to utilize the variety of food materials found in splashpools, including: detritus and organic floes; superficial material on particles; faecal pellets; protists; diatoms; and small crustaceans. From light and scanning electron microscopy and video, the labrum and labium appear to be adapted for biting soft and hard food materials and holding food for trituration by the mandibles. From energy dispersive X-ray spectra, the gnathobase of the mandible is suggested to be sclerotized but not calcified or silicified. It has an array of bilobate and multilobate teeth, clusters of spinous processes, and a heavy, spine-bearing process to move food into the oesophagus. There is also a flange which articulates in a groove in the labrum which appears to provide a guide for the gnathobase as it moves vertically.

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Importance of potassium ions for ribosome structure and function revealed by long-wavelength X-ray diffraction

Nature Communications ◽

10.1038/s41467-019-10409-4 ◽

2019 ◽

Vol 10 (1) ◽

Cited By ~ 34

Author(s):

Alexey Rozov ◽

Iskander Khusainov ◽

Kamel El Omari ◽

Ramona Duman ◽

Vitaliy Mykhaylyk ◽

...

Keyword(s):

Structure And Function ◽

Potassium Ions ◽

X Ray Diffraction ◽

X Ray ◽

Long Wavelength ◽

Ribosome Structure ◽

And Function

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Enhanced photobactericidal activity of ZnO nanorods modified by meso-tetrakis(4-sulfonatophenyl)porphyrin under visible LED lamp irradiation

Water Science & Technology ◽

10.2166/wst.2015.098 ◽

2015 ◽

Vol 71 (8) ◽

pp. 1249-1254 ◽

Cited By ~ 9

Author(s):

Rahmatollah Rahimi ◽

Javad Shokraiyan ◽

Mahboubeh Rabbani ◽

Fatemeh Fayyaz

Keyword(s):

Electron Microscopy ◽

Escherichia Coli ◽

Diffuse Reflectance ◽

Zno Nanorods ◽

X Ray Diffraction ◽

X Ray ◽

Template Free ◽

Inorganic Composite ◽

Scanning Electron ◽

Better Than

In this study, zinc oxide (ZnO) nanorods have been synthesized using a simple template-free precipitation technique and deposited on glass substrate. The meso-tetrakis(4-sulfonatophenyl)porphyrin (TPPS) has been synthesized and then immobilized on the surface of ZnO nanorods to prepare an organic/inorganic composite. The samples were characterized by various techniques such as X-ray diffraction, diffuse reflectance spectra, Fourier transform-infrared spectroscopy and scanning electron microscopy. In addition, the photobactericidal activity of TPPS/ZnO composite, TPPS and ZnO nanorods was tested against the pathogenic bacterium of Escherichia coli under visible LED lamp irradiation. The results indicate that the photobactericidal activity of TPPS-loaded ZnO nanorods was better than TPPS or ZnO nanorods, separately.

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THE RELATION BETWEEN STRUCTURE AND FUNCTION IN HEMOGLOBINS

Canadian Journal of Biochemistry ◽

10.1139/o64-088 ◽

1964 ◽

Vol 42 (6) ◽

pp. 763-775 ◽

Cited By ~ 7

Author(s):

Austen Riggs

Keyword(s):

Structural Changes ◽

Structure And Function ◽

Bohr Effect ◽

X Ray Diffraction ◽

X Ray ◽

Subunit Dissociation ◽

And Function ◽

Polypeptide Chains ◽

Protein Structure Data ◽

Lines Of Evidence

Many lines of evidence indicate that the oxygenation of hemoglobin is accompanied by changes in protein structure. Data on the oxygen equilibria of the hemoglobins from a number of animals are discussed in terms of this evidence. Evidence from studies of some hemoglobins (lamprey, frog and tadpole) indicates a major role for subunit dissociation equilibria in explaining two properties of the oxygen equilibria: heme–heme interaction and the "Bohr effect". The importance of subunit dissociation in mammalian hemoglobins is suggested by the known concentration dependence of the oxygen equilibria. Mammalian hemoglobins are composed of two types of polypeptide chains, α and β. The idea that the α and β subunits have different oxygen equilibria and are affected differently by pH is examined. It is concluded that the β-chains appear to play a major role in the mechanism of the Bohr effect not shared by the α-chains. This conclusion is supported by the structural changes in hemoglobin found to occur upon oxygenation by X-ray diffraction techniques.

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Synthesis of nano-zinc oxide with different morphologies and its application on fabrics for UV protection and microbe-resistant defense clothing

Textile Research Journal ◽

10.1177/0040517520920952 ◽

2020 ◽

Vol 90 (21-22) ◽

pp. 2492-2503

Author(s):

MA Mousa ◽

M Khairy

Keyword(s):

Electron Microscopy ◽

Escherichia Coli ◽

Scanning Electron Microscopy ◽

Staphylococcus Aureus ◽

Zinc Oxide ◽

X Ray Diffraction ◽

X Ray ◽

Nano Zinc Oxide ◽

Nano Zinc ◽

Scanning Electron

A liquid precipitation method was used to prepare zinc oxide nanoparticles in three diverse media: water, methanol, and ethylene glycol. The studied materials were examined by scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and ultraviolet-visible spectroscopy. X-ray diffraction patterns showed a hexagonal Wurtzite structure of zinc oxide with a nanocrystalline size. Acquired powders showed different morphologies (rod, star, and spherical structures), which were affected by the nature of the solvent in the reaction. The different zinc oxide powders have varied optical band gaps. Scanning electron microscopy examinations confirmed the arrangement of nano-zinc oxide on the surfaces of the materials. The zinc oxide-covering procedure was carried out on cotton, polyester, and 50/50 wt% polyester/cotton blended fabrics using a simple dip and curing system. The cotton fabric treated with nanorod zinc oxide exhibited the highest ultraviolet protection factor with a value of 247.2. The antimicrobial properties of untreated and treated fabrics with nano-zinc oxide were measured against Gram-negative bacteria (Escherichia coli), Gram-positive bacteria (Staphylococcus aureus), and diploid fungus (Candida albicans). The results showed the antimicrobial action relies on the morphological structure and the particle size of zinc oxide and that it increases with a reduced particle size. The cotton fabric treated with 26 nm nonspherical zinc oxide particles showed the highest antimicrobial efficiency with values of 91.4%, 86.8%, and 84.7% for Staphylococcus aureus, Escherichia coli, and Candida albicans, respectively. The mechanical properties of treated fabrics were studied. The results confirm that nano-zinc oxide is highly useful for improving the performance of defense textile products because of its biocompatibility, environmental friendliness, and nontoxicity.

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The Study of Calcium Oxide from Cockle Shell Used as a Low-Cost Catalyzer for Biodiesel Production

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.879.108 ◽

2018 ◽

Vol 879 ◽

pp. 108-112 ◽

Cited By ~ 1

Author(s):

Nisakorn Nuamsrinuan ◽

Pichet Limsuwan ◽

Kittisakchai Naemchanthara

Keyword(s):

Calcium Oxide ◽

Low Cost ◽

Structure And Function ◽

Biodiesel Production ◽

Resonance Spectroscopy ◽

X Ray Diffraction ◽

X Ray ◽

Function Group ◽

And Function ◽

Cockle Shell

In this paper, the cockle shell was studied as a catalyzer for biodiesel production. The cockle shell was heated at the various temperatures from 200 to 1300 °C for 4 h in the furnace. Then, the crystal structure and function group of unheated and heated cockle shell were characterized by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR), respectively. The results indicated that the initial phase of cockle shell is aragonite phase. After heat at 400 °C, the aragonite phase transformed to calcite phase. Moreover, the calcite phase of cockle shell was completely changed to calcium oxide (CaO) after heated at 800 °C. Eventually, the yield of biodiesel used the CaO derived from cockle shell were determined by nuclear magnetic resonance spectroscopy (NMR). The results show that the CaO derived from cockle shell can be used as a catalyzer of biodiesel preparation. However, the biodiesel used CaO from cockle shell after heated at 1100 to 1300 °C as a catalyzer have the higher yield than other heated temperature. Finally, the results of this research indicated that the CaO from cockle shell could be used as a catalyst for biodiesel production.

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