scholarly journals Step-Wise Hydration of Magnesium by Four Water Molecules Precedes Phosphate Release in a Myosin Motor

2021 ◽  
Vol 125 (4) ◽  
pp. 1107-1117
Author(s):  
Mauro Lorenzo Mugnai ◽  
D. Thirumalai
Keyword(s):  
Water Molecules ◽  
Phosphate Release ◽  
Myosin Motor

Swing of the lever arm of a myosin motor at the isomerization and phosphate-release steps

Nature ◽  
10.1038/24640 ◽  
1998 ◽  
Vol 396 (6709) ◽  
pp. 380-383 ◽  
Author(s):  
Yoshikazu Suzuki ◽  
Takuo Yasunaga ◽  
Reiko Ohkura ◽  
Takeyuki Wakabayashi ◽  
Kazuo Sutoh
Keyword(s):  
Phosphate Release ◽  
Myosin Motor ◽  
Lever Arm

scholarly journals Step-wise Hydration of Magnesium by Four Water Molecules Precedes Phosphate Release in a Myosin Motor

2019 ◽  
Author(s):  
M.L. Mugnai ◽  
D. Thirumalai
Keyword(s):  
Molecular Motors ◽  
Atp Hydrolysis ◽  
Structural Similarity ◽  
Nucleotide Binding ◽  
Binding Pocket ◽  
Water Molecules ◽  
Myosin Vi ◽  
Phosphate Release ◽  
Myosin Motors ◽  
Dynamics Simulations

AbstractMolecular motors, such as myosin, kinesin, and dynein, convert the energy released by the hydrolysis of ATP into mechanical work, which allows them to undergo directional motion on cytoskeletal tracks. This process is achieved through synchronization between the catalytic activity of the motor and the associated changes in its conformation. A pivotal step in the chemomechanical transduction in myosin motors occurs after they bind to the actin filament, which triggers the release of phosphate (Pi, product of ATP hydrolysis) and the rotation of the lever arm. Here, we investigate the mechanism of phosphate release in myosin VI, which has been debated for over two decades, using extensive molecular dynamics simulations involving multiple trajectories each several μs long. Because the escape of phosphate is expected to occur on time-scales on the order of milliseconds in myosin VI, we observed Pi release only if the trajectories were initiated with a rotated phosphate inside the nucleotide binding pocket. The rotation provided the needed perturbation that enabled successful expulsions of Pi in several trajectories. Analyses of these trajectories lead to a robust mechanism of Pi release in the class of motors belonging to the myosin super family. We discovered that although Pi populates the traditional “back door” route, phosphate exits through various other gateways, thus establishing the heterogeneity in the escape routes. Remarkably, we observe that the release of phosphate is preceded by a step-wise hydration of the ADP-bound magnesium ion. In particular, the release of the anion occurred only after four water molecules hydrate the cation (Mg2+). By performing comparative structural analyses, we suggest that the hydration of magnesium is the key step in the phosphate release in a number of ATPases and GTPases that share a similar structure in the nucleotide binding pocket. Thus, nature may have evolved hydration of Mg2+ by discrete water molecules as a general molecular switch for Pi release, which is a universal step in the catalytic cycle of many machines which share little sequence or structural similarity.

Utilization of electrical charges in the pores of tofu waste for hydrogen production in water

2020 ◽  
pp. 124-135
Author(s):  
I. N. G. Wardana ◽  
N. Willy Satrio
Keyword(s):  
Magnetic Field ◽  
Hydrogen Production ◽  
Sodium Bicarbonate ◽  
Positive Charge ◽  
Electrical Energy ◽  
Hydrogen Sensor ◽  
Water Molecules ◽  
Partial Charge ◽  
Delocalized Electron ◽  
Water Hydrogen

Tofu is main food in Indonesia and its waste generally pollutes the waters. This study aims to change the waste into energy by utilizing the electric charge in the pores of tofu waste to produce hydrogen in water. The tofu pore is negatively charged and the surface surrounding the pore has a positive charge. The positive and negative electric charges stretch water molecules that have a partial charge. With the addition of a 12V electrical energy during electrolysis, water breaks down into hydrogen. The test was conducted on pre-treated tofu waste suspension using oxalic acid. The hydrogen concentration was measured by a MQ-8 hydrogen sensor. The result shows that the addition of turmeric together with sodium bicarbonate to tofu waste in water, hydrogen production increased more than four times. This is due to the fact that magnetic field generated by delocalized electron in aromatic ring in turmeric energizes all electrons in the pores of tofu waste, in the sodium bicarbonate, and in water that boosts hydrogen production. At the same time the stronger partial charge in natrium bicarbonate shields the hydrogen proton from strong attraction of tofu pores. These two combined effect are very powerful for larger hydrogen production in water by tofu waste.

PEMANFAATAN GLISERIN DARI RESIDU GLISERIN SEBAGAI PLASTICIZER UNTUK PEMBUATAN BIOPLASTIK DENGAN BAHAN BAKU PATI BONGGOL PISANG KEPOK

2017 ◽  
Vol 5 (4) ◽  
pp. 26-32 ◽  
Author(s):  
Azaria Robiana ◽  
M. Yashin Nahar ◽  
Hamidah Harahap
Keyword(s):  
Tensile Strength ◽  
Hydrogen Bonding ◽  
Fatty Acid ◽  
Maximum Yield ◽  
Sem Analysis ◽  
Water Molecules ◽  
Banana Weevil ◽  
Gelatinization Temperature ◽  
Recharge Area ◽  
Maximum Quantity

Glycerin residue is waste oleochemical industry that still contain glycerin. To produce quality and maximum quantity of glycerin, then research the effect of pH acidification using phosphoric acid. Glycerin analysis includes the analysis of pH, Fatty Acid and Ester (FAE), and analysis of the levels of glycerin. The maximum yield obtained at pH acidification 2 is grading 91,60% glycerin and Fatty Acid and Ester (FAE) 3,63 meq/100 g. Glycerin obtained is used as a plasticizer in the manufacture of bioplastics. Manufacture of bioplastics using the method of pouring a solution with varying concentrations of starch banana weevil (5% w/v and 7% w/v), variations of the addition of glycerin (1 ml, 3 ml, 5 ml and 7 ml), and a variety of gelatinization temperature (60°C, 70°C, and 80°C). Analysis of bioplastics include FTIR testing, tensile strength that is supported by SEM analysis. The results obtained in the analysis of FTIR does not form a new cluster on bioplastics starch banana weevil, but only a shift in the recharge area only, it is due to the addition of O-H groups originating from water molecules that enter the polysaccharide through a mechanism gelatinitation that generates interaction hydrogen bonding strengthened. The maximum tensile strength of bioplastics produced at a concentration of starch 7% w/v, 1 ml glycerine and gelatinization temperature of 80°C is 3,430 MPa. While the tensile strength bioplastic decreased with increasing glycerin which can be shown from the results of SEM where there is a crack, indentations and lumps of starch insoluble.

An infrared assay of the kinetics of phosphate-release from physiological substrates in living cells

2014 ◽  
Author(s):  
Ren Zhongyuan ◽  
Do Leduy ◽  
Saida Mebarek ◽  
Nermin Keloglu ◽  
Saandia Ahamada ◽  
...  
Keyword(s):  
Living Cells ◽  
Phosphate Release ◽  
Kinetics Of ◽  
Physiological Substrates

Calculation of Equilibrium Constant for Dimerization of Heavy Water Molecules in Saturated Vapor

2015 ◽  
Vol 60 (3) ◽  
pp. 263-267
Author(s):  
L.A. Bulavin ◽  
◽  
S.V. Khrapatyi ◽  
V.M. Makhlaichuk ◽  
Keyword(s):  
Equilibrium Constant ◽  
Heavy Water ◽  
Saturated Vapor ◽  
Water Molecules

Long-Term Correlations In Diffusive Motion Of Water Molecules And Rare Gas Atoms In Helium And Argon Aqueous Solutions

2015 ◽  
Vol 60 (8) ◽  
pp. 757-763 ◽  
Author(s):  
V.P. Voloshin ◽  
◽  
G.G. Malenkov ◽  
Yu.I. Naberukhin ◽  
◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Rare Gas ◽  
Water Molecules ◽  
Diffusive Motion ◽  
Rare Gas Atoms

Structural Study of a new Compound Based on Acid 1,4-Cyclohexanedicarboxylic (1,4-CDC)

2010 ◽  
Vol 6 (1) ◽  
pp. 891-896
Author(s):  
Manel Halouani ◽  
M. Dammak ◽  
N. Audebrand ◽  
L. Ktari
Keyword(s):  
Aqueous Solution ◽  
Water Molecules ◽  
Carboxyl Group ◽  
X Ray Diffraction ◽  
Compound I ◽  
Unit Cell Parameters ◽  
Monoclinic System ◽  
X Ray ◽  
Cell Parameters ◽  
Cyclohexanedicarboxylic Acid

One nickel 1,4-cyclohexanedicarboxylate coordination polymers, Ni2 [(O10C6H4)(COO)2].2H2O  (I), was hydrothermally synthesized from an aqueous solution of Ni (NO3)2.6H2O, (1,4-CDC) (1,4-CDC = 1,4-cyclohexanedicarboxylic acid) and tetramethylammonium nitrate. Compound (I) crystallizes in the monoclinic system with the C2/m space group. The unit cell parameters are a = 20.1160 (16) Å, b = 9.9387 (10) Å, c = 6.3672 (6) Å, β = 97.007 (3) (°), V= 1263.5 (2) (Å3) and Dx= 1.751g/cm3. The refinement converged into R= 0.036 and RW = 0.092. The structure, determined by single crystal X-ray diffraction, consists of two nickel atoms Ni (1) and Ni (2). Lots of ways of which is surrounded by six oxygen atoms, a carboxyl group and two water molecules.

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