Quantum dot based enzyme activity sensors present deviations from Michaelis-Menten kinetic model

2016 ◽  
Author(s):  
Sebastián A. Díaz ◽  
Carl W. Brown ◽  
Anthony P. Malanoski ◽  
Eunkeu Oh ◽  
Kimihiro Susumu ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Kinetic Model ◽  
Quantum Dot ◽  
Activity Sensors ◽  
Menten Kinetic

scholarly journals A kinetic model of ferrous iron oxidation by Acidithiobacillus ferrooxidans in a batch culture

2005 ◽  
Vol 11 (2) ◽  
pp. 59-62 ◽  
Author(s):  
Dragisa Savic ◽  
Miodrag Lazic ◽  
Vlada Veljkovic ◽  
Miroslav Vrvic
Keyword(s):  
Kinetic Model ◽  
Acidithiobacillus Ferrooxidans ◽  
Ferrous Iron ◽  
Bubble Column ◽  
Iron Oxidation ◽  
Yield Coefficient ◽  
Transfer Rates ◽  
Ferrous Iron Oxidation ◽  
Menten Kinetic ◽  
Kinetics Of

The batch oxidation kinetics of ferrous iron by Acidithiobacillus ferrooxidans were examined at different oxygen transfer rates and pH in an aerated stirred tank and a bubble column. The microbial growth, oxygen consumption rate and ferrous and ferric iron were monitored during the biooxidation. A kinetic model was established on the basis of the Michaelis-Menten kinetic equation for bacterial growth and the constants estimated from experimental data (maximum specific growth rate 0.069 h-1, saturation constant 2.9 g/dm3, and biomass yield coefficient based on ferrous iron 0.003 gd.w./gFe). Values calculated from the model agreed well with the experimental ones regardless of the bioreactor type and pH conditions.

Quantum dot-based nanosensors for diagnosis via enzyme activity measurement

2013 ◽  
Vol 13 (4) ◽  
pp. 367-375 ◽  
Author(s):  
Birgitta R Knudsen ◽  
Morten Leth Jepsen ◽  
Yi-Ping Ho
Keyword(s):  
Enzyme Activity ◽  
Quantum Dot ◽  
Activity Measurement

Kinetic model of intermixing during self-assembled InAs quantum dot formation

2007 ◽  
Vol 301-302 ◽  
pp. 692-696 ◽  
Author(s):  
Ch. Heyn ◽  
A. Schramm ◽  
T. Kipp ◽  
W. Hansen
Keyword(s):  
Kinetic Model ◽  
Quantum Dot ◽  
Self Assembled ◽  
Inas Quantum Dot

Proteolytic Activity at Quantum Dot-Conjugates: Kinetic Analysis Reveals Enhanced Enzyme Activity and Localized Interfacial “Hopping”

Nano Letters ◽  
2012 ◽  
Vol 12 (7) ◽  
pp. 3793-3802 ◽  
Author(s):  
W. Russ Algar ◽  
Anthony Malonoski ◽  
Jeffrey R. Deschamps ◽  
Juan B. Blanco-Canosa ◽  
Kimihiro Susumu ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Quantum Dot ◽  
Kinetic Analysis ◽  
Proteolytic Activity

scholarly journals Total enzyme activity constraint and homeostatic constraint impact on the optimization potential of a kinetic model

Biosystems ◽  
2017 ◽  
Vol 162 ◽  
pp. 128-134 ◽  
Author(s):  
Vitalijs Komasilovs ◽  
Agris Pentjuss ◽  
Atis Elsts ◽  
Egils Stalidzans
Keyword(s):  
Enzyme Activity ◽  
Kinetic Model ◽  
Total Enzyme Activity ◽  
Total Enzyme

scholarly journals Multiplicity of carotene patterns derives from competition between phytoene desaturase diversification and biological environments

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Mathieu Fournié ◽  
Gilles Truan
Keyword(s):  
Kinetic Model ◽  
Phylogenetic Tree ◽  
Functional Data ◽  
Kinetic Data ◽  
Binding Constants ◽  
Reaction Rates ◽  
Phytoene Desaturase ◽  
Bacterial System ◽  
Lycopene Cyclase ◽  
Menten Kinetic

AbstractPhytoene desaturases catalyse from two to six desaturation reactions on phytoene, generating a large diversity of molecules that can then be cyclised and produce, depending on the organism, many different carotenoids. We constructed a phylogenetic tree of a subset of phytoene desaturases from the CrtI family for which functional data was available. We expressed in a bacterial system eight codon optimized CrtI enzymes from different clades. Analysis of the phytoene desaturation reactions on crude extracts showed that three CrtI enzymes can catalyse up to six desaturations, forming tetradehydrolycopene. Kinetic data generated using a subset of five purified enzymes demonstrate the existence of characteristic patterns of desaturated molecules associated with various CrtI clades. The kinetic data was also analysed using a classical Michaelis–Menten kinetic model, showing that variations in the reaction rates and binding constants could explain the various carotene patterns observed. Competition between lycopene cyclase and the phytoene desaturases modified the distribution between carotene intermediates when expressed in yeast in the context of the full β-carotene production pathway. Our results demonstrate that the desaturation patterns of carotene molecules in various biological environments cannot be fully inferred from phytoene desaturases classification but is governed both by evolutionary-linked variations in the desaturation rates and competition between desaturation and cyclisation steps.

scholarly journals Optimization and Kinetic Modelling of The Enzymatic Hydrolysis of Oil Palm Petioles

2017 ◽  
Vol 2 (6) ◽  
pp. 439
Author(s):  
Efri Mardawatia ◽  
Dwi Wahyudha Wira ◽  
M. Djali ◽  
Fetriyuna Fetriyuna ◽  
Edi Suryadi
Keyword(s):  
Enzymatic Hydrolysis ◽  
Kinetic Model ◽  
Kinetic Parameters ◽  
Oil Palm ◽  
Kinetic Modelling ◽  
Raw Material ◽  
Surface Response Method ◽  
Response Method ◽  
Menten Kinetic ◽  
Hydrolysis Of

Oil palm petiole is  the solid waste  of the crude palm oil industry.  It contains about 35% cellulose, 18% hemicellulose and 22-25% lignin.  During hydrolysis   lingo celllulosic, cellulose and hemicellulose are gradually degraded into fermentable sugars, such as glucose and xylose. Enzymatic hydrolysis of oil palm petioleby xylanase could be an effective biotechnological process, since it can be performed at ambient temperature and pressure. Further glucose and xylose can be used as raw material for the production of a wide variety of chemicals such as xylitol and bioethanol. The aim of this study wasto examine the optimum conditions needed for the enzymatic hydrolysis  of oil palm petioles, particularly temperature and pH. A surface Response Method Methodologies  (RSM) by central composite design (CCD) was employed to obtain  the optimum xylose concentration.   The dynamics of enzymatic hydrolysis   process was modelled using the Michaelis Menten kinetic model with kinetic parameters obtained from   experimental data. The results of this study lead to an enhanced process of the enzymatic hydrolysis of oil palm petiole, whichwas shown to follow the Michaelis Menten kinetic  model and the kinetic parameters including Km and Vm were obtained, they were 6.433 g/L  andVm= 0.042 g/L/min. The optimum hydrolysis condition wereobserved to be at temperature 50oC and pH 4.8. Keywords: enzymatic hydrolysis; glucose; kinetic modelling; oil palm petioles; xylose

Morphological and biochemical analyses of changes in rat hepatocytes related to wine and ethanol consumption

1984 ◽  
Vol 42 ◽  
pp. 232-233
Author(s):  
S.M. Geyer ◽  
C.L. Mendenhall ◽  
J.T. Hung ◽  
E.L. Cardell ◽  
R.L. Drake ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Enzyme Activity ◽  
Malic Enzyme ◽  
Smooth Endoplasmic Reticulum ◽  
Rat Hepatocytes ◽  
Mature Male ◽  
Treatment Groups ◽  
Malic Enzyme Activity ◽  
Biochemical Analyses

Thirty-three mature male Holtzman rats were randomly placed in 3 treatment groups: Controls (C); Ethanolics (E); and Wine drinkers (W). The animals were fed synthetic diets (Lieber type) with ethanol or wine substituted isocalorically for carbohydrates in the diet of E and W groups, respectively. W received a volume of wine which provided the same gram quantity of alcohol consumed by E. The animals were sacrificed by decapitation after 6 weeks and the livers processed for quantitative triglycerides (T3), proteins, malic enzyme activity (MEA), light microscopy (LM) and electron microscopy (EM). Morphometric analysis of randomly selected LM and EM micrographs was performed to determine organellar changes in centrilobular (CV) and periportal (PV) regions of the liver. This analysis (Table 1) showed that hepatocytes from E were larger than those in C and W groups. Smooth endoplasmic reticulum decreased in E and increased in W compared to C values.

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