Single enzyme electroanalysis

The Analyst ◽  
2021 ◽  
Author(s):  
Kathryn J. Vannoy ◽  
Andrey Ryabykh ◽  
Andrei I. Chapoval ◽  
Jeffrey E. Dick
Keyword(s):  
Experimental Approach ◽  
Electrochemical Methods ◽  
Kinetics Of ◽  
Enzyme Reactivity ◽  
Single Enzyme

Traditional enzymology relies on the kinetics of millions of enzymes, an experimental approach that may wash out heterogeneities between individual enzymes. Electrochemical methods have emerged in the last 5 years to probe single enzyme reactivity.

scholarly journals Importance of rheology in the prediction of structural transition phenomena in geopolymer matrices loaded with phosphogypsum

2019 ◽  
Vol 286 ◽  
pp. 07005
Author(s):  
N. Lahlou ◽  
M. Ouazzani Touhami ◽  
R. Hattaf ◽  
R. Moussa
Keyword(s):  
Rheological Behavior ◽  
Structural Transition ◽  
Experimental Approach ◽  
Fresh State ◽  
Hardened State ◽  
Definition Of ◽  
The Impact ◽  
Kinetics Of

Through a purely experimental approach, we proceed here to the description of the rheological behavior of the geopolymer matrices in the fresh state according to one or other of the parameters characterizing their formulation. This consolidates the different physicochemical techniques usually used for their characterization. This comes to allow us especially the definition of drafts for the implementation of empirical laws ensuring a better follow-up in the elaboration of these materials or even more optimization in their formulation. This description also allows us to follow the structural transition phenomena from the fresh state to the hardened state. We are particularly interested in demonstrating the impact of the addition of Phosphogypsum on the rheological behavior of geopolymers or on their kinetics of setting.

Preliminary study on the kinetics of oxytetracycline in shellfish exposed to an effluent of a land-based fish farm: Experimental approach

1995 ◽  
Vol 40 (2) ◽  
pp. 171-180 ◽  
Author(s):  
Hervé Le Bris ◽  
Hervé Pouliquen ◽  
Jean-Marc Debernardi ◽  
Vincent Buchet ◽  
Louis Pinault
Keyword(s):  
Experimental Approach ◽  
Fish Farm ◽  
Preliminary Study ◽  
Kinetics Of

Titelbild: Single-Enzyme Kinetics of CALB-Catalyzed Hydrolysis (Angew. Chem. 4/2005)

2005 ◽  
Vol 117 (4) ◽  
pp. 499-499
Author(s):  
Kelly Velonia ◽  
Ophir Flomenbom ◽  
Davey Loos ◽  
Sadahiro Masuo ◽  
Mircea Cotlet ◽  
...  
Keyword(s):  
Enzyme Kinetics ◽  
Kinetics Of ◽  
Single Enzyme

scholarly journals Studies of the acetylcholinesterase from houseflies (Musca domestica L.) resistant and susceptible to organophosphorus insecticides

1975 ◽  
Vol 149 (2) ◽  
pp. 463-469 ◽  
Author(s):  
A L Devonshire
Keyword(s):  
Musca Domestica ◽  
Rate Constants ◽  
Gel Electrophoresis ◽  
Organophosphorus Compounds ◽  
Organophosphorus Insecticides ◽  
Triton X ◽  
Kinetics Of ◽  
Kinetics Of Inhibition ◽  
Single Enzyme

Acetylcholinesterase from the heads of insecticide-resistant and -susceptible houseflies (Musca domestica L.) was studied in vitro. The enzymes could not be distinguished electrophoretically, and their behaviour on polyacrylamide-disc-gel electrophoresis was influenced by the presence of Triton X-100 in both the homogenate and the gels. In the absence of detergent, the acetylcholinesterase was heterogeneous, but behaved as a single enzyme when it was present. By analogy with studies of acetylcholinesterase from other sources, these observations were attributed to aggregation of the enzyme when not bound by membranes. The enzyme from resistant flies was more slowly inhibited than the susceptible enzyme, bimolecular rate constants (ki) differing by approx. 4-20-fold for a range of organophosphorus compounds. The kinetics of inhibition of acetylcholinesterase were consistent with the results of electrophoresis, i.e. they corresponded to those of a single enzyme in the presence of Triton X-100, but a mixture of enzymes in its absence. The susceptibility of the more sensitive components in these mixtures was determined.

scholarly journals Influence of high heating rates on evolution of oxides on directed laser energy additively fabricated IN718

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Sangram Mazumder ◽  
Mangesh V. Pantawane ◽  
Narendra B. Dahotre
Keyword(s):  
Photoelectron Spectroscopy ◽  
Room Temperature ◽  
Experimental Approach ◽  
Laser Energy ◽  
Isothermal Treatment ◽  
Thermal Treatments ◽  
Heating Rates ◽  
Temperature Oxidation ◽  
Fe Oxides ◽  
Kinetics Of

AbstractThe effect of non-isothermal treatment in oxygen-containing air, via heating rates of 10, 50, and 1000 °C/min until 1000 °C followed by furnace cooling to room temperature on oxides formed on directed laser energy additively fabricated IN718 was studied. Another set of samples heated up to 1000 °C using the same heating rates were isothermally held at 1000 °C for 1 hr followed by furnace cooling to room temperature. X-ray photoelectron spectroscopy indicated the presence of NiO on samples only heated at 1000 °C/min. Also, results indicated the absence of Fe-oxides on non-isothermally treated samples, irrespective of heating rate. However, isothermal treatment confirmed the presence of NiO on all samples and Fe-oxides on samples heated via 50 and 1000 °C/min. The durations in complement with the kinetics of the thermal treatments influenced oxide evolution in the samples. Such an experimental approach was adopted to study the material response under dynamic short duration-high temperature oxidation.

Kinetics of Allosteric Inhibition of Single Enzyme by Product Molecules

2020 ◽  
Vol 124 (52) ◽  
pp. 11793-11801
Author(s):  
Prasanta Kundu ◽  
Soma Saha ◽  
Gautam Gangopadhyay
Keyword(s):  
Allosteric Inhibition ◽  
Kinetics Of ◽  
Single Enzyme

Single Lipid Vesicle Assay for Characterizing Single-Enzyme Kinetics of Phospholipid Hydrolysis in a Complex Biological Fluid

2013 ◽  
Vol 135 (38) ◽  
pp. 14151-14158 ◽  
Author(s):  
Seyed R. Tabaei ◽  
Michael Rabe ◽  
Henrik Zetterberg ◽  
Vladimir P. Zhdanov ◽  
Fredrik Höök
Keyword(s):  
Enzyme Kinetics ◽  
Biological Fluid ◽  
Lipid Vesicle ◽  
Phospholipid Hydrolysis ◽  
Kinetics Of ◽  
Single Enzyme

Interfacial reactions in multilayers intended for microelectronics devices

1998 ◽  
Vol 514 ◽  
Author(s):  
X. Federspiel ◽  
F. Voiron ◽  
M. Ignat ◽  
T. Marieb ◽  
H. Fujimoto
Keyword(s):  
Phase Formation ◽  
Reaction Rate ◽  
Experimental Approach ◽  
Intermetallic Phase ◽  
Activation Energies ◽  
Interfacial Reactions ◽  
Scanning Calorimetry ◽  
Back Scattering ◽  
Apparent Activation Energies ◽  
Kinetics Of

ABSTRACTThe knowledge of the reaction kinetics which can occur at an interface of a couple of materials, remains a crucial issue to establish the structural limits of a diffusion barrier intended for microelectronic structures.In the past years, the interfacial reactions activated at an interface of a couple of materials, as for example aluminum and titanium, have been analyzed extensively using different experimental tools, as for example: Ruthreford Back Scattering (thickness determination) and Differential Scanning Calorimetry (DSC). Then, these experimental methods were useful to deduce parameters, characterizing the interfacial reactions in bulk samples: apparent activation energies, enthalpy of formation. Because in thin films, the kinetics of the reactions that can be activated at an interface will be different; we studied interfacial reactions in submicronic Al/Ti layers.Taking advantage of the accuracy of the DSC (reaction rate determinations and detection of earlier stages of intermetallic phase formation), our experimental approach consisted in a series of isothermal and non-isothermal DSC experiments on submicron Al/Ti layered structures. From the reaction rate determination, analytical methods as the Kissinger Ozawa approach were used, to determine the apparent activation energies of the phase formation. Also the results allowed to model and discuss the first steps of the interfacial reaction.

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