Reactions of ZnR2 Compounds with Dibenzoyl: Characterisation of the Alkyl-Transfer Products and a Striking Product-Inhibition Effect

2011 ◽  
Vol 17 (45) ◽  
pp. 12713-12721 ◽  
Author(s):  
Izabela Dranka ◽  
Marcin Kubisiak ◽  
Iwona Justyniak ◽  
Michał Lesiuk ◽  
Dominik Kubicki ◽  
...  
Keyword(s):  
Product Inhibition ◽  
Inhibition Effect ◽  
Alkyl Transfer

scholarly journals Corrigendum: Reactions of ZnR2 Compounds with Dibenzoyl: Characterisation of the Alkyl-Transfer Products and a Striking Product-Inhibition Effect

2012 ◽  
Vol 18 (6) ◽  
pp. 1557-1557
Author(s):  
Izabela Dranka ◽  
Marcin Kubisiak ◽  
Iwona Justyniak ◽  
Michał Lesiuk ◽  
Dominik Kubicki ◽  
...  
Keyword(s):  
Product Inhibition ◽  
Inhibition Effect ◽  
Alkyl Transfer

scholarly journals A tris(benzyltriazolemethyl)amine-based cage as a CuAAC ligand tolerant to exogeneous bulky nucleophiles

2021 ◽  
Author(s):  
Gege Qiu ◽  
Paola Nava ◽  
Alexandre Martinez ◽  
Cédric Colomban
Keyword(s):  
Product Inhibition ◽  
Inhibition Effect

The canonical CuAAC–ligand TBTA was capped with a bowl-shaped unit yielding the cage Hm-TBTA. The shielded structure does not suffer from product inhibition effect and is remarkably tolerant to the biological CuAAC-inhibitor Glutathione.

Extractive Fermentation of Ethanol from Fresh Cassava Roots Using Vacuum Fractionation Technique

2014 ◽  
Vol 931-932 ◽  
pp. 1096-1100 ◽  
Author(s):  
Supathra Phakping ◽  
Mariena Ketudat-Cairns ◽  
Apichat Boontawan
Keyword(s):  
Simultaneous Saccharification And Fermentation ◽  
Ethanol Concentration ◽  
Fermentation Broth ◽  
Product Inhibition ◽  
Raw Material ◽  
Yeast Cells ◽  
Batch Mode ◽  
Inhibition Effect ◽  
Vacuum Fractionation ◽  
Simultaneous Saccharification

Fresh cassava roots were used as a raw material for ethanol fermentation. Conventional batch mode (CF), simultaneous saccharification and fermentation (SSF) and simultaneous liquefaction, saccharification and fermentation (SLSF) were investigated with various enzyme systems. The ethanol concentrations obtained in batch fermentations ranged from 8-12 wt%. In addition, vacuum fractionating technique was successfully introduced to simultaneously remove high purity ethanol from fermentation broth in batch mode. The distilled ethanol concentration was approximately 86 wt% whilst its concentration in the bioreactor was kept lower than 2 wt%. As a result, the product inhibition effect to yeast cells was reduced.

scholarly journals Structural Basis for the Mechanistic Understanding of Human CD38-controlled Multiple Catalysis

2006 ◽  
Vol 281 (43) ◽  
pp. 32861-32869 ◽  
Author(s):  
Qun Liu ◽  
Irina A. Kriksunov ◽  
Richard Graeff ◽  
Cyrus Munshi ◽  
Hon Cheung Lee ◽  
...  
Keyword(s):  
Nicotinamide Adenine Dinucleotide ◽  
Reaction Pathway ◽  
Structural Data ◽  
Product Inhibition ◽  
Structural Basis ◽  
Oh Groups ◽  
Inhibition Effect ◽  
Oxocarbenium Ion ◽  
Polar Interactions ◽  
Covalently Linked

The enzymatic cleavage of the nicotinamide-glycosidic bond on nicotinamide adenine dinucleotide (NAD+) has been proposed to go through an oxocarbenium ion-like transition state. Because of the instability of the ionic intermediate, there has been no structural report on such a transient reactive species. Human CD38 is an ectoenzyme that can use NAD+ to synthesize two calcium-mobilizing molecules. By using NAD+ and a surrogate substrate, NGD+, we captured and determined crystal structures of the enzyme complexed with an intermediate, a substrate, and a product along the reaction pathway. Our results showed that the intermediate is stabilized by polar interactions with the catalytic residue Glu226 rather than by a covalent linkage. The polar interactions between Glu226 and the substrate 2′,3′-OH groups are essential for initiating catalysis. Ser193 was demonstrated to have a regulative role during catalysis and is likely to be involved in intermediate stabilization. In addition, a product inhibition effect by ADP-ribose (through the reorientation of the product) or GDP-ribose (through the formation of a covalently linked GDP-ribose dimer) was observed. These structural data provide insights into the understanding of multiple catalysis and clues for drug design.

scholarly journals Kinetic Analysis Misinterpretations Due to the Occurrence of Enzyme Inhibition by Reaction Product: Comparison between Initial Velocities and Reaction Time Course Methodologies

2021 ◽  
Vol 12 (1) ◽  
pp. 102
Author(s):  
Joana M. C. Fernandes ◽  
Albino A. Dias ◽  
Rui M. F. Bezerra
Keyword(s):  
Kinetic Analysis ◽  
Enzyme Inhibition ◽  
Initial Velocity ◽  
Time Course ◽  
Product Inhibition ◽  
Experimental Point ◽  
Inhibition Effect ◽  
Product Comparison ◽  
Data Points ◽  
Enzymatic Product

The Michaelis–Menten equation (MME) has been extensively used in biochemical reactions, but it is not appropriate when the reaction product inhibits the enzyme. Under these circumstances, each determined initial velocity, v0, is one experimental point that actually belongs to a different MME because enzymatic product inhibition occurs as the reaction starts. Furthermore, the inhibition effect is not constant, since the concentration of the product inhibitor rises as time increases. To unveil the hidden enzyme inhibition and to simultaneously demonstrate the superiority of an integrated Michaelis–Menten equation (IMME), the same range of data points, assuming product inhibition and the presence of a second different inhibitor, was used for kinetic analysis with both methodologies. This study highlights the superiority of the IMME methodology for when the enzyme is inhibited by the reaction product, giving a more coherent inhibition model and more accurate kinetic constants than the classical MME methodology.

Inter-individual variability in clopidogrel inhibition effect on platelet aggregation

2018 ◽  
Vol 9 (SPL1) ◽  
Author(s):  
Hussein Ali Sahib ◽  
Bassim Irhiem Mohammed ◽  
Ban A. Abdul Majid
Keyword(s):  
Cardiovascular Disease ◽  
Platelet Aggregation ◽  
Coronary Care Unit ◽  
Light Transmission ◽  
Individual Variability ◽  
Study Group ◽  
Inhibition Effect ◽  
Light Transmission Aggregometry ◽  
Coronary Care ◽  
Skewness And Kurtosis

Despite the unmistakable beneficial effect of clopidogrel on platelet aggregation,still there are some patient poorly responds to clopidogrel that may lead to worse cardiovascular clinical events.One hundred and twenty seven patients with cardiovascular disease (ACS,stroke,or TIA) were enrolled as a study group. Patients were recruited at coronary care unit (CCU) of Al-Yarmouk Teaching Hospital. Paletlet assessment was done by using light transmission aggregometry. between the patients that enrolled in this study there are significant inter-individual variability both skewness and Kurtosis were negative (-0.450,-0.130) respectively. 24% of patient enrolled in this study were hyporesponder.

Inhibition Effect Extract Stolephorus insularis as a Antimicroba in Staphylococcus aereus Bacteria

DENTA ◽  
2018 ◽  
Vol 12 (1) ◽  
pp. 22
Author(s):  
Ayu Listya ◽  
Yulie Emilda Akhwan
Keyword(s):  
Staphylococcus Aureus ◽  
Root Canal ◽  
Quantitative Research ◽  
Media Culture ◽  
Root Canal Treatment ◽  
Research Needs ◽  
Dmso Solution ◽  
Entire Surface ◽  
Inhibition Effect ◽  
Inhibitory Power

<pre><em><strong>Background :</strong> U</em><em>ntreated caries will continue and microorganisms enter the pulp resulting in an inflammatory response and pulp necrosis. Sterilization is one part of root canal treatment and is important for the success of root canal treatment. Stolephorus insularis contains antibacterial substances such as fluor. Previous research showed that extract Stolephorus insularis has antibacterial activity in Streptococcus mutans bacteria.</em><em></em></pre><pre><em>Purpose : T</em><em>his study aims to determine the antibacterial power of Stolephorus insularis extract on the growth of Staphylococcus aereus bacteria by using 3 concentrations of 18%, 24% and 30%.</em></pre><pre><em>Material and Method :</em><em>This resesarch use culture of Staphylococcus aereus bacteria in MH blood agar, Stolephorus insularis extract with various concentrations (18%, 24%, 30%), 7% Na CMC, 1% DMSO solution, agar BHI media. Culture of Staphylococcus aereus was taken from liquid BHI media, then rubbed on the entire surface of BHI media using a sterile cotton stick. The antibacterial zone formed is measured.</em></pre><pre> </pre><pre><em>Result : B</em><em>ased on the results of the Mann-Whitney test there were significant differences in the inhibitory power of Staphylococcus aureus bacteria (p &lt;0.05) in the K + group with groups K-, P1, P2 and P3. Whereas between groups P1 with K-, group P2 with K- and P1, and group P3 with K-, P1 and P2 there were no significant differences because the significant value was greater than 0.05</em><em></em></pre><pre><em>Conclusion : T</em><em>here is no antimicrobial power at concentrations of 18%, 24%, and 30%. Quantitative research needs to be done to determine the decrease in the number of bacterial colonies.</em><em></em></pre><p><em><br /></em></p><p><em><strong>Keywords :</strong> Inhibition effect, Stolephorus insularis, Staphylococcus aereus</em></p><p><em><br /></em></p><p><em><strong>Correspondence :</strong> </em><em>Ayulistya Paramita, Paediatric Departemen. FKG UHT, Jl Arief Rahman Hakim no 150 Surabaya. email : [email protected]</em></p>

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