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

2019 ◽  
Vol 10 (1) ◽  
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

THE RELATION BETWEEN STRUCTURE AND FUNCTION IN HEMOGLOBINS

1964 ◽  
Vol 42 (6) ◽  
pp. 763-775 ◽  
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.

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

2018 ◽  
Vol 879 ◽  
pp. 108-112 ◽  
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.

Crystal Structures of Fragments D and Double-D from Fibrinogen and Fibrin

1999 ◽  
Vol 82 (08) ◽  
pp. 271-276 ◽  
Author(s):  
Glen Spraggon ◽  
Stephen Everse ◽  
Russell Doolittle
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Crystal Structures ◽  
Structure And Function ◽  
X Ray ◽  
Long Period ◽  
And Function

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

scholarly journals Betp - X-Ray Structure and Function of An Osmosensor and Transporter

2010 ◽  
Vol 98 (3) ◽  
pp. 46a
Author(s):  
Reinhard Kraemer ◽  
Susanne Ressl ◽  
Vera Ott ◽  
Sascha Nicklisch ◽  
Heinz-Juergen Steinhoff ◽  
...  
Keyword(s):  
Structure And Function ◽  
X Ray ◽  
And Function

Investigation of Magnetic Order in Iron Oxide-Nickel Oxide Superlattices with Modulation Wavelength Less Than 80 Å

1991 ◽  
Vol 231 ◽  
Author(s):  
S. D. Berry ◽  
D. M. Lind ◽  
G. Chern ◽  
H. Mathias ◽  
L. R. Testardi
Keyword(s):  
Magnetic Order ◽  
Spontaneous Magnetization ◽  
X Ray Diffraction ◽  
High Crystalline Quality ◽  
X Ray ◽  
Long Wavelength ◽  
Saturation Moment ◽  
Very High ◽  
Modulation Wavelength

AbstractWe have investigated the magnetic order, using SQUID magnetometry, for short modulation wavelength Fe3O4/NiO superlattices, grown on single crystal MgO. Ferrimagnetic Fe3O4 has a saturation moment of ~500 emu/cm3 at 0 K and a Curie temperature of 858 K, while bulk NiO is antiferromagnetic with a NMel temperature of 525 K. Very high crystalline quality with little interdiffusion is indicated by X-ray diffraction, SEM, optical microscopy, and in-situ RHEED, and the samples show highly anisotropic electrical conductivity which also indicates the strong modulation present. Long wavelength samples (Amod > 200 Å) have a behavior only slightly different from that expected from bulk Fe3O4, but for Amod<80 Å, spontaneous magnetization is replaced by paramagnetism, with weak temperature dependence (not I/T) from 5 K to 400 K.

scholarly journals Evolutionary Conservation of Reactions in Translation

2002 ◽  
Vol 66 (3) ◽  
pp. 460-485 ◽  
Author(s):  
M. Clelia Ganoza ◽  
Michael C. Kiel ◽  
Hiroyuki Aoki
Keyword(s):  
Molecular Mechanisms ◽  
Tertiary Structure ◽  
Evolutionary Conservation ◽  
Initiation Factor ◽  
Structural Studies ◽  
X Ray Diffraction ◽  
X Ray ◽  
Common Features ◽  
New Information ◽  
And Function

SUMMARY Current X-ray diffraction and cryoelectron microscopic data of ribosomes of eubacteria have shed considerable light on the molecular mechanisms of translation. Structural studies of the protein factors that activate ribosomes also point to many common features in the primary sequence and tertiary structure of these proteins. The reconstitution of the complex apparatus of translation has also revealed new information important to the mechanisms. Surprisingly, the latter approach has uncovered a number of proteins whose sequence and/or structure and function are conserved in all cells, indicating that the mechanisms are indeed conserved. The possible mechanisms of a new initiation factor and two elongation factors are discussed in this context.

scholarly journals New photochromic salt spiropyrans of indoline series

2019 ◽  
Vol 484 (6) ◽  
pp. 698-702
Author(s):  
A. D. Pugachev ◽  
M. B. Lukyanova ◽  
V. V. Tkachev ◽  
B. S. Lukyanov ◽  
N. I. Makarova ◽  
...  
Keyword(s):  
Absorption Band ◽  
Diffraction Analysis ◽  
Hypsochromic Shift ◽  
X Ray Diffraction ◽  
Photochromic Properties ◽  
Photoinduced Form ◽  
X Ray ◽  
Long Wavelength

The synthesis and study of the structure and photochromic properties of the new salt spiropyrans of the indoline series containing chlorine and bromine atoms as a substituent at the 6' position in 2H-chromene moiety are presented. The structure of the obtained compounds was confirmed by NMR 1H spectroscopy and X-ray diffraction analysis. The compounds are photochromic; the long-wavelength maximum of the absorption band of their open photoinduced form has a significant hypsochromic shift, and the lifetime substantially increases in comparison with the fluorine analog.

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