Reversible Light‐Responsive Coacervate Microdroplets with Rapid Regulation of Enzymatic Reaction Rate

2021 ◽  
Author(s):  
Yan Huang ◽  
Xiaoliang Wang ◽  
Junbo Li ◽  
Youping Lin ◽  
Haixu Chen ◽  
...  
Keyword(s):  
Reaction Rate ◽  
Enzymatic Reaction

Enzymatic Reaction Kinetics of Papain-Extracted Collagen from Bighead Carp Scales

2015 ◽  
Vol 727-728 ◽  
pp. 56-60
Author(s):  
Min Li ◽  
Liu Meng Chen ◽  
Bo Quan Jiang
Keyword(s):  
Reaction Kinetics ◽  
Reaction Rate ◽  
Enzymatic Reaction ◽  
Raw Material ◽  
Bighead Carp ◽  
Fish Waste ◽  
Biomedical Material ◽  
Production Output ◽  
And Control ◽  
Kinetics Of

Collagen, as an important biomedical material, has been widely used in medical industry. Fish waste (scales, skins, bones, fins and swim bladders) is a kind of newly developed alternative collagen raw material.This paper uesd papain as enzyme and local bighead fish scales as raw material to extract collagen. More attention was paid to the study on enzymatic reaction kinetics of papain-extracted collagen. The results showed that two kinds of kinetic models(Michaelis-Menten equations and exponential type dynamic equations) at 20, 25 and 28°C were established, respectively and experimentally proved to be basically in agreement with the actual values. These models have a great significance to predict, adjust and control the reaction rate and production output under different conditions.

Optimized Determination of γ-Glutamyltransferase by Reaction-Rate Analysis

1974 ◽  
Vol 20 (9) ◽  
pp. 1121-1124 ◽  
Author(s):  
Sidney B Rosalki ◽  
David Tarlow
Keyword(s):  
Dilute Hydrochloric Acid ◽  
Reaction Rate ◽  
Enzymatic Reaction ◽  
Enzyme Reaction ◽  
Enzyme Reactions ◽  
Rate Analysis ◽  
Acid Substrate ◽  
Incubation Buffer ◽  
Optimal Ph

Abstract We describe a method for measuring γ-glutamyltransferase (EC 2.3.2.2) activity in serum, which can be used with automated enzyme analyzers (such as the LKB 8600 Reaction Rate Analyzer) that require enzyme reactions to be initiated with substrate. The method also permits optimal determination conditions to be obtained at 37 °C. The enzymatic reaction is commenced by adding γ-glutamyl-p-nitroanilide dissolved in dilute hydrochloric acid to samples pre-incubated with tris(hydroxymethyl)aminomethane—glycylglycine buffer. The p-nitroaniline liberated is continously monitored at 37 °C at 405 nm. The pH of the pre-incubation buffer is such that the optimal pH for the enzyme reaction results from addition of the acid substrate solution.

scholarly journals A Multi-Scale Approach to Modeling the Interfacial Reaction Kinetics of Lipases with Emphasis on Enzyme Adsorption at Water-Oil Interfaces

Processes ◽  
2020 ◽  
Vol 8 (9) ◽  
pp. 1082
Author(s):  
Sherly Rusli ◽  
Janna Grabowski ◽  
Anja Drews ◽  
Matthias Kraume
Keyword(s):  
Reaction Kinetics ◽  
Surface Area ◽  
Reaction Rate ◽  
Enzymatic Reaction ◽  
Interfacial Area ◽  
Enzyme Adsorption ◽  
Multi Scale ◽  
Specific Interfacial Area ◽  
Enzyme Molecules ◽  
Interfacial Adsorption

The enzymatic hydrolysis of triglycerides with lipases (EC 3.1.1.3.) involves substrates from both water and oil phases, with the enzyme molecules adsorbed at the water-oil (w/o) interface. The reaction rate depends on lipase concentration at the interface and the available interfacial area in the emulsion. In emulsions with large drops, the reaction rate is limited by the surface area. This effect must be taken into account while modelling the reaction. However, determination of the interfacial saturation is not a trivial matter, as enzyme molecules have the tendency to unfold on the interface, and form multi-layer, rendering many enzyme molecules unavailable for the reaction. A multi-scale approach is needed to determine the saturation concentration with specific interfacial area so that it can be extrapolated to droplet swarms. This work explicitly highlights the correlation between interfacial adsorption and reaction kinetics, by integration of the adsorption kinetics into the enzymatic reaction. The rate constants were fitted globally against data from both single droplet and drop swarm experiments. The amount of adsorbed enzymes on the interface was measured in a single drop with a certain surface area, and the enzyme interfacial loading was estimated by Langmuir adsorption isotherm.

Automated Enzymatic Determination of L-Lactate in Serum, with Use of a Miniature Centrifugal Anlyzer

1976 ◽  
Vol 22 (12) ◽  
pp. 2038-2041 ◽  
Author(s):  
T P Hadjiioannou ◽  
S I Hadjiioannou ◽  
S D Brunk ◽  
H V Malmstadt
Keyword(s):  
Lactate Dehydrogenase ◽  
Reaction Rate ◽  
Enzymatic Reaction ◽  
Reaction Rates ◽  
Enzymatic Determination ◽  
Analytical Recovery ◽  
Rate Method ◽  
Relative Errors ◽  
Lithium Lactate

Abstract We describe an automated enzymatic reaction-rate method for spectrophotometric determination of lactate in serum with a miniature centrifugal analyzer. The L(+)-lactate is selectively oxidized in the presence of lactate dehydrogenase (EC 1.1.1.27) and NAD+ to from NADH, whitch is measured from its absorption. Reaction rates are determined automatically, and unknown concentrations are calculated from a computer0generated calibration curve with aqueous lithium lactate standards. Lactte concentrations in the range 0.32-1.6 µg/4 µl (80-400 mg/liter) of sample were determined with relative errors and coefficient of variation of 4.8%. Analytical recovery of lactate added to pooled serum was 89-112% (average, 101%). Comparison with a kit ("Rapid Lactate") method gave a correlation coefficient squared of 0.979 over a concentration range of 39-779 mg/liter.

Relation of Enzymatic Reaction Rate and Hydrophobicity of the Solvent

1992 ◽  
pp. 229-235 ◽  
Author(s):  
J. Bert ◽  
A. van Tol ◽  
Jan B. Odenthal ◽  
Jaap A. Jongejan ◽  
Johannis A. Duine
Keyword(s):  
Reaction Rate ◽  
Enzymatic Reaction

Hydrolysis Characteristics of Over Fermented Tempe (Fermented Soybean Cake) Product Hydrolyzed by Enzymatic Hydrolysis as Natural Flavor Source (Flavor Enhancer)

2018 ◽  
Vol 55 (1) ◽  
pp. 29
Author(s):  
, Mujianto ◽  
Yuli Witono ◽  
, Wignyanto ◽  
Sri Kumalaningsih ◽  
Auliani’am ,
Keyword(s):  
Enzymatic Hydrolysis ◽  
Reaction Rate ◽  
Block Design ◽  
Enzymatic Reaction ◽  
Antioxidant Power ◽  
Hydrolysis Process ◽  
Randomized Complete Block Design ◽  
Soybean Cake ◽  
Total Sediment ◽  
Flavor Enhancer

The purpose of this study is to be acknowledged of the characteristics of protein hydrolyzed from enzymatic hydrolysis process of rejected tempe. The parameters of rejected Tempe hydrolysis characteristics are dissoluble protein, dissoluble total sediment, maillard intensity, hydrolytic color, namely color L, color a, color b, whiteness, chrome and hue, level of staleness, antioxidant power, water activity, hydrolysis level, enzymatic reaction rate, HPLC amino acid and hydrolytic FTIR of over fermentedtempe. This study is designed using Randomized Complete Block Design with 3 (three) blocks as repetition. The result of this study indicates that the highest Hydrolysis Level (HL) belongs to Flavorzyme enzyme (10.3% HL), Protamex (8.4% HL) and Calontropin (7.1% HL) with enzymatic reaction rate for Flavorzyme enzyme is V max as much as 0.01727 mg per ml per minute, while the content of glutamate acid in hydrolyzed over fermented-tempe reaches 15.95%.

A single-liquid miniature biofuel cell with boosting power density via gas diffusion bioelectrodes

2020 ◽  
Vol 8 (16) ◽  
pp. 3550-3556 ◽  
Author(s):  
Jing Wan ◽  
Li Mi ◽  
Zhaoyan Tian ◽  
Quan Li ◽  
Songqin Liu
Keyword(s):  
Power Density ◽  
Power Output ◽  
Active Sites ◽  
Reaction Rate ◽  
Enzymatic Reaction ◽  
Gas Diffusion ◽  
Gas Diffusion Electrode ◽  
Maximum Power ◽  
Biofuel Cell ◽  
Maximum Power Output

A single-liquid glucose–O2 cell is constructed by gas diffusion electrode. O2 diffusion directly from air to active sites of enzyme enhances the enzymatic reaction rate. The maximum power output density of the cell is 53 μW cm−2.

Fixed-time kinetic assay of plasma ammonia, with NADPH as cofactor, with a centrifugal analyzer.

1979 ◽  
Vol 25 (4) ◽  
pp. 611-613 ◽  
Author(s):  
P K Li ◽  
B C Shull
Keyword(s):  
Reaction Rate ◽  
Enzymatic Reaction ◽  
Fixed Time ◽  
Kinetic Assay ◽  
Plasma Ammonia ◽  
Standard Curve ◽  
Analytical Recovery ◽  
Silver Spring ◽  
Catalytic Amination ◽  
Preincubation Time

Abstract We describe a fixed-time, enzymatic, reaction-rate procedure for determining plasma ammonia with a centrifugal analyzer (Rotochem IIA/36; American Instrument Co., silver Spring, MD 20910), with NADPH as cofactor. The reaction is based on that of da Fonseca-Wollheim's modification [J. Clin. Chem. Clin. Biochem. 11, 421 (1973)] of the Kirstein reaction, which depends on the catalytic amination of alpha-ketoglutarate by the action of glutamate dehydrogenase with NADPH as the cofactor instead of NADH. Use of NADPH minimizes interference from endogenous reactions such as that between lactate dehydrogenase and pyruvate. This method permits shortened preincubation time and thus improves both specificity and precision. This assay requires 100 microliter of freshly collected heparinized plasma, gives quantitative analytical recovery, and the standard curve is linear to 430 mumol/L. Data are presented comparing results with those by two other enzymatic ammonia procedures.

Instabilities in a Simple Enzyme Reaction Caused by pH-Dependence

1995 ◽  
Vol 50 (12) ◽  
pp. 1147-1150 ◽  
Author(s):  
Gerold Baier ◽  
Peter Strasser ◽  
Ursula Kummer
Keyword(s):  
Reaction Rate ◽  
Ph Dependence ◽  
Enzymatic Reaction ◽  
Enzyme Reaction ◽  
Reaction Diffusion ◽  
Temporal Patterns ◽  
Homogeneous Reactor ◽  
Spatio Temporal

Abstract We investigate the model of an enzymatic reaction with Michaelis-Menten kinetics and bell-shaped pH-dependence of the reaction rate. In the case of proton consumption the reaction can generate oscillations in a homogeneous reactor and turbulent spatio-temporal patterns in a reaction-diffusion environment. I n s t a b il it i e s in a S im p le E n z y m e R e a c tio n C a u s e d b y p H -D e p e n d e n c e *

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