scholarly journals Controlled Anchoring of (Phenylureido)sulfonamide-Based Receptor Moieties: An Impact of Binding Site Multiplication on Complexation Properties

Molecules ◽  
2021 ◽  
Vol 26 (18) ◽  
pp. 5670
Author(s):  
Karolína Salvadori ◽  
Alena Krupková ◽  
Lucie Červenková Šťastná ◽  
Monika Müllerová ◽  
Václav Eigner ◽  
...  
Keyword(s):  
Binding Site ◽  
1H Nmr ◽  
Binding Mode ◽  
Spectroscopic Studies ◽  
Dihydrogen Phosphate ◽  
Receptor Molecule ◽  
Receptor Structure ◽  
Anion Complexation ◽  
Dendritic Branches ◽  
The Way

The repetition of urea-based binding units within the receptor structure does not only lead to monomer properties multiplication. As confirmed by spectroscopic studies, UV-Vis and 1H-NMR in classical or competitive titration mode, the attachment to a carrier allocates the active moieties to mutual positions predetermining the function of the whole receptor molecule. Bivalent receptors form self-aggregates. Dendritic receptors with low dihydrogen phosphate loadings offer a cooperative complexation mode associated with a positive dendritic effect. In higher dihydrogen phosphate concentrations, the dendritic branches act independently and the binding mode changes to 1:1 anion: complexation site. Despite the anchoring, the dendritic receptors retain the superior efficiency and selectivity of a monomer, paving the way to recyclable receptors, desirable for economic and ecological reasons.

A New Reactive Ketenaminal: Synthesis, Coupling Reaction, Tautomeric Study, Docking and Antimicrobial Evaluation of the Products

2020 ◽  
Vol 16 (6) ◽  
pp. 761-773
Author(s):  
Huda K. Mahmoud ◽  
Hanadi A. Katouah ◽  
Marwa F. Harras ◽  
Thoraya A. Farghaly
Keyword(s):  
Binding Site ◽  
Antimicrobial Agents ◽  
Coupling Reaction ◽  
Docking Study ◽  
Binding Mode ◽  
Binding Energies ◽  
Simple Method ◽  
Antimicrobial Evaluation ◽  
New Compounds ◽  
Active Methylene

Background: One of the most successful reagents used in the synthesis of the reactive enaminone is DMF-DMA, but it is very expensive with harmful effects on the human health and reacts with special compounds to generate the enaminone such as active methylene centers. Aim: In this article, we synthesized a new ketenaminal by simple method with inexpensive reagents (through desulfurization in diphenylether). Methods: Thus, a novel reactive ketenaminal (enaminone) was synthesized from the desulfurization of 2-((2-(4-chlorophenyl)-2-oxoethyl)thio)-5,7-bis(4-methoxyphenyl)pyrido[2,3-d]pyrimidin- 4(3H)-one with diphenylether. The starting keteneaminal was coupled with diazotized anilines via the known coupling conditions to give a new series of 2-(4-chlorophenyl)-1-(2-(arylhydrazono)-2- oxoethyl)-5,7-bis(4-methoxy-phenyl)pyrido[2,3-d]pyrimidin-4(1H)-ones. Results: The structures of the new compounds were elucidated based on their IR, 1H-NMR, 13CNMR, and Mass spectra. Moreover, the potency of these compounds as antimicrobial agents has been evaluated. The results showed that some of the products have high activity nearly equal to that of the used standard antibiotic. Additionally, the docking study was done to get the binding mode of the synthesized compounds with the binding site of the DHFR enzyme. The results of molecular docking of the synthesized arylhydrazono compounds are able to fit in DHFR binding site with binding energies ranging from -4.989 to -8.178 Kcal/mol. Conclusion: Our goal was achieved in this context by the synthesis of new ketenaminal from inexpensive reagents, which was utilized in the preparation of bioactive arylhydrazone derivatives.

scholarly journals Structural and functional studies of pyruvate carboxylase regulation by cyclic di-AMP in lactic acid bacteria

2017 ◽  
Vol 114 (35) ◽  
pp. E7226-E7235 ◽  
Author(s):  
Philip H. Choi ◽  
Thu Minh Ngoc Vu ◽  
Huong Thi Pham ◽  
Joshua J. Woodward ◽  
Mark S. Turner ◽  
...  
Keyword(s):  
Binding Site ◽  
Conformational Changes ◽  
Pyruvate Carboxylase ◽  
Adenosine Monophosphate ◽  
Binding Mode ◽  
Functional Studies ◽  
Cellular Processes ◽  
Wide Range ◽  
A Site ◽  
Amp Inhibition

Cyclic di-3′,5′-adenosine monophosphate (c-di-AMP) is a broadly conserved bacterial second messenger that has been implicated in a wide range of cellular processes. Our earlier studies showed that c-di-AMP regulates central metabolism inListeria monocytogenesby inhibiting its pyruvate carboxylase (LmPC), a biotin-dependent enzyme with biotin carboxylase (BC) and carboxyltransferase (CT) activities. We report here structural, biochemical, and functional studies on the inhibition ofLactococcus lactisPC (LlPC) by c-di-AMP. The compound is bound at the dimer interface of the CT domain, at a site equivalent to that in LmPC, although it has a distinct binding mode in the LlPC complex. This binding site is not well conserved among PCs, and only a subset of these bacterial enzymes are sensitive to c-di-AMP. Conformational changes in the CT dimer induced by c-di-AMP binding may be the molecular mechanism for its inhibitory activity. Mutations of residues in the binding site can abolish c-di-AMP inhibition. InL. lactis, LlPC is required for efficient milk acidification through its essential role in aspartate biosynthesis. The aspartate pool inL. lactisis negatively regulated by c-di-AMP, and high aspartate levels can be restored by expression of a c-di-AMP–insensitive LlPC. LlPC has high intrinsic catalytic activity and is not sensitive to acetyl-CoA activation, in contrast to other PC enzymes.

scholarly journals Insights into the binding mode of MEK type-III inhibitors. A step towards discovering and designing allosteric kinase inhibitors across the human kinome

2016 ◽  
Author(s):  
Zheng Zhao ◽  
Lei Xie ◽  
Philip E. Bourne
Keyword(s):  
Molecular Dynamics ◽  
Binding Site ◽  
Protein Kinases ◽  
Drug Targets ◽  
Kinase Inhibitors ◽  
Binding Mode ◽  
Dynamics Simulation ◽  
Allosteric Inhibitors ◽  
Type Iii ◽  
Human Kinome

AbstractProtein kinases are critical drug targets for treating a large variety of human diseases. Type-I and type-II kinase inhibitors frequently exhibit off-target toxicity or lead to mutation acquired resistance. Two highly specific allosteric type-III MEK-targeted drugs, Trametinib and Cobimetinib, offer a new approach. Thus, understanding the binding mechanism of existing type-III kinase inhibitors will provide insights for designing new type-III kinase inhibitors. In this work we have systematically studied the binding mode of MEK-targeted type-III inhibitors using structural systems pharmacology and molecular dynamics simulation. Our studies provide detailed sequence, structure, interaction-fingerprint, pharmacophore and binding-site information on the binding characteristics of MEK type-III kinase inhibitors. We propose that the helix-folding activation loop is a hallmark allosteric binding site for type-III inhibitors. Subsequently we screened and predicted allosteric binding sites across the human kinome, suggesting other kinases as potential targets suitable for type-III inhibitors. Our findings will provide new insights into the design of potent and selective kinases inhibitors.Author SummaryHuman protein kinases represent a large protein family relevant to many diseases, especially cancers, and have become important drug targets. However, developing the desired selective kinase-targeted inhibitors remain challenging. Kinase allosteric inhibitors provide that opportunity, but, to date, few have been designed other than MEK inhibitors. To more efficiently develop kinase allosteric inhibitors, we systematically studied the binding mode of the MEK type-III allosteric kinase inhibitors using structural system pharmacology and molecular dynamics approaches. New insights into the binding mode and mechanism of type-III inhibitors were revealed that may facilitate the design of new prospective type-III kinase inhibitors.

scholarly journals Super Extended Calix[4]Pyrroles as Candidate for Binding Mercury

2018 ◽  
Vol 34 (6) ◽  
pp. 2789-2795
Author(s):  
Maan Al-Nuaim ◽  
H. N. K. AL-Salman ◽  
Hussein H. Hussein
Keyword(s):  
Thermodynamic Parameters ◽  
Organic Solvents ◽  
1H Nmr ◽  
Strong Interaction ◽  
Ester Group ◽  
Hydroxyl Group ◽  
Ester Derivative ◽  
Anion Complexation ◽  
Calorimetric Studies ◽  
Complexation Process

The binding of mercury Hg (II) by calix[4]pyrrole derivative; 2 has been much less discovered than anion complexation. The presence of hydroxyl group in the structure of meso-tetramethyl-tetrakis-[2(4-hydroxyphenyl)ethylcalix[4]pyrrole is important for further modifications in the next steps. The modification of the hydroxyl group by the substitution of ester group was carried out to produce the ester derivative for the modified calix[4]pyrrole 2. The ester group would be expected to deliver high electronic contributions in the complexation processes with the guests as well as to increase the solubility of the receptor in different organic solvents. 1H NMR and isothermal titration calorimetric studies revealed that the receptors exhibited strong interaction with mercury cation and the complexation process was driven enthalpically and entropically. Conductance measurements in acetonitrile were carried out to identify the composition of the formed complex. From Nano Isothermal Titration Calorimetric studies, the thermodynamic parameters for the complexation processes were calculated.

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