scholarly journals The phosphorylation mechanism of mevalonate diphosphate decarboxylase: a QM/MM study

2020 ◽  
Vol 18 (3) ◽  
pp. 518-529 ◽  
Author(s):  
James McClory ◽  
Chenggong Hui ◽  
Jian Zhang ◽  
Meilan Huang
Keyword(s):  
Magnesium Ions ◽  
Phosphorylation Reaction ◽  
Mevalonate Diphosphate Decarboxylase ◽  
Phosphorylation Mechanism

Combined MD and QM/MM studies suggested that mevalonate diphosphate decarboxylase requires two magnesium ions for a phosphorylation reaction.

Observations of the Thermal Decomposition of Brucite

1968 ◽  
Vol 26 ◽  
pp. 446-447
Author(s):  
P. L. Burnett ◽  
W. R. Mitchell ◽  
C. L. Houck
Keyword(s):  
Thermal Decomposition ◽  
Magnesium Oxide ◽  
Basal Plane ◽  
Magnesium Ions ◽  
A Value ◽  
Reaction Proceeds

Natural Brucite (Mg(OH)2) decomposes on heating to form magnesium oxide (MgO) having its cubic ﹛110﹜ and ﹛111﹜ planes respectively parallel to the prism and basal planes of the hexagonal brucite lattice. Although the crystal-lographic relation between the parent brucite crystal and the resulting mag-nesium oxide crystallites is well known, the exact mechanism by which the reaction proceeds is still a matter of controversy. Goodman described the decomposition as an initial shrinkage in the brucite basal plane allowing magnesium ions to shift their original sites to the required magnesium oxide positions followed by a collapse of the planes along the original <0001> direction of the brucite crystal. He noted that the (110) diffraction spots of brucite immediately shifted to the positions required for the (220) reflections of magnesium oxide. Gordon observed separate diffraction spots for the (110) brucite and (220) magnesium oxide planes. The positions of the (110) and (100) brucite never changed but only diminished in intensity while the (220) planes of magnesium shifted from a value larger than the listed ASTM d spacing to the predicted value as the decomposition progressed.

The Effect of Agents which Modify Platelet Behaviour and of Magnesium Ions on Thrombus Formation In Vivo

1979 ◽  
Vol 42 (02) ◽  
pp. 603-610 ◽  
Author(s):  
J H Adams ◽  
J R A Mitchell
Keyword(s):  
Thrombus Formation ◽  
Cerebral Arteries ◽  
Magnesium Ions ◽  
Body Formation ◽  
Inflammatory Agent ◽  
Platelet Thrombus ◽  
Magnesium Salts ◽  
Higher Doses ◽  
Do So

SummaryThe ability of potential anti-thrombotic agents to modify platelet-thrombus formation in injured cerebral arteries in the rabbit was tested. Low doses of heparin were without effect, while higher doses produced variable suppression of white body formation but at the expense of bleeding. Aspirin did not inhibit white body formation but another non-steroid anti-inflammatory agent, flurbiprofen was able to do so, as was the anti-gout agent, sulphinpyrazone. Magnesium salts both topically and parenterally, suppressed thrombus formation and increased the concentration of ADP which was required to initiate thrombus production at minor injury sites.

Effect of substitution on the mechanism of conductivity of ultra dispersed lithium - iron spinel, substituted with magnesium ions

2017 ◽  
Vol 9 (5) ◽  
pp. 05018-1-05018-6
Author(s):  
B. K. Ostafiychuk ◽  
◽  
L. S. Kaykan ◽  
J. S. Mazurenko ◽  
B. Ya. Deputat ◽  
...  
Keyword(s):  
Magnesium Ions

Abiotic reduction of 2,4-dinitrotoluene in the presence of sulfide minerals under anoxic conditions

1996 ◽  
Vol 34 (10) ◽  
pp. 25-33 ◽  
Author(s):  
Cheng Jiayang ◽  
Makram T. Suidan ◽  
Albert D. Venosa
Keyword(s):  
Electron Donor ◽  
Chemical Reduction ◽  
Sulfide Minerals ◽  
Sulfide Concentration ◽  
Magnesium Ions ◽  
High Concentration ◽  
Anoxic Conditions ◽  
High Affinity ◽  
Iron Nickel ◽  
Abiotic Reduction

Abiotic reduction of 2,4-dinitrotoluene (DNT) in the presence of sulfide minerals has been investigated under anoxic conditions at 35°C. 2,4-DNT was abiotically reduced to 4-amino-2-nitrotoluene (4-A-2-NT) and 2-amino-4-nitrotoluene (2-A-4-NT) in the presence of high concentration of sulfide (0.84 mM). No abiotic reduction of 2,4-DNT was observed in the presence of low sulfide concentration (0.42 mM). The rate and the extent of the abiotic reduction of 2,4-DNT were increased with an increase in sulfide concentration. Sulfide served as an electron donor for the reduction of 2,4-DNT. The 2-nitro group was preferentially reduced, making the 2-A-4-NT:4-A-2-NT ratio in the final products 2:1. The addition of iron, nickel, and cobalt minerals significantly enhanced the abiotic reduction. The FeS, NiS, and CoS solids formed in the serum bottles catalyzed the reduction of 2,4-DNT preferentially to 4-A-2-NT. MnS and CuS solids also catalyzed the reduction of 2,4-DNT to 4-A-2-NT, but did not change the overall reduction of 2,4-DNT. However, the presence of calcium, zinc, and magnesium minerals impeded 2,4-DNT reduction. The calcium, zinc, and magnesium ions have a high affinity to sulfide, inactivating sulfide as an electron donor for the chemical reduction of 2,4-DNT.

scholarly journals Pure hydroxyapatite synthesis originating from amorphous calcium carbonate

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Michika Sawada ◽  
Kandi Sridhar ◽  
Yasuharu Kanda ◽  
Shinya Yamanaka
Keyword(s):  
Calcium Carbonate ◽  
Calcium Phosphate ◽  
Room Temperature ◽  
Molar Ratio ◽  
Final Phase ◽  
Amorphous Calcium Carbonate ◽  
Phosphate Compound ◽  
Synthesis Strategy ◽  
Phosphorylation Reaction ◽  
Subsequent Calcination

AbstractWe report a synthesis strategy for pure hydroxyapatite (HAp) using an amorphous calcium carbonate (ACC) colloid as the starting source. Room-temperature phosphorylation and subsequent calcination produce pure HAp via intermediate amorphous calcium phosphate (ACP). The pre-calcined sample undergoes a competitive transformation from ACC to ACP and crystalline calcium carbonate. The water content, ACC concentration, Ca/P molar ratio, and pH during the phosphorylation reaction play crucial roles in the final phase of the crystalline phosphate compound. Pure HAp is formed after ACP is transformed from ACC at a low concentration (1 wt%) of ACC colloid (1.71 < Ca/P < 1.88), whereas Ca/P = 1.51 leads to pure β-tricalcium phosphate. The ACP phases are precursors for calcium phosphate compounds and may determine the final crystalline phase.

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