scholarly journals Thiazide and other Cl-benzenesulfonamide-bearing clinical drug affinities for human carbonic anhydrases

PLoS ONE ◽  
2021 ◽  
Vol 16 (6) ◽  
pp. e0253608
Author(s):  
Lina Baranauskiene ◽  
Lina Škiudaitė ◽  
Vilma Michailovienė ◽  
Vytautas Petrauskas ◽  
Daumantas Matulis

Twelve carbonic anhydrase (CA) isoforms catalyze carbon dioxide hydration to bicarbonate and acid protons and are responsible for many biological functions in human body. Despite their vital functions, they are also responsible for, or implicated in, numerous ailments and diseases such as glaucoma, high altitude sickness, and cancer. Because CA isoforms are highly homologous, clinical drugs designed to inhibit enzymatic activity of a particular isoform, can also bind to others with similar affinity causing toxic side effects. In this study, the affinities of twelve CA isoforms have been determined for nineteen clinically used drugs used to treat hypertension related diseases, i.e. thiazides, indapamide, and metolazone. Their affinities were determined using a fluorescent thermal shift assay. Stopped flow assay and isothermal titration calorimetry were also employed on a subset of compounds and proteins to confirm inhibition of CA enzymatic activity and verify the quantitative agreement between different assays. The findings of this study showed that pharmaceuticals could bind to human CA isoforms with variable affinities and inhibit their catalytic activity, even though the drug was intended to interact with a different (non-CA) protein target. Relatively minor structural changes of the compounds may cause significant changes in affinity and selectivity for a particular CA isoform.

2020 ◽  
Vol 27 ◽  
Author(s):  
Justina Kazokaitė-Adomaitienė ◽  
Holger M. Becker ◽  
Joana Smirnovienė ◽  
Ludwig J. Dubois ◽  
Daumantas Matulis

Background: Carbonic anhydrases (CAs) regulate pH homeostasis via the reversible hydration of CO2, thereby emerging as essential enzymes for many vital functions. Among 12 catalytically active CA isoforms in humans, CA IX has become a relevant therapeutic target because of its role in cancer progression. Only two CA IX inhibitors have entered clinical trials mostly due to low affinity and selectivity properties. Objective: The current review presents the design, development, and identification of the selective nano- to picomolar CA IX inhibitors VD11-4-2, VR16-09, and VD12-09. Methods and Results: Compounds were selected from our database, composed of over 400 benzensulfonamides, synthesized at our laboratory, and tested for their binding to 12 human CAs. Here we discuss the CA CO2 hydratase activity/inhibition assay and several biophysical techniques, such as fluorescent thermal shift assay and isothermal titration calorimetry, highlighting their contribution to the analysis of compound affinity and structure-activity relationships. To obtain sufficient amounts of recombinant CAs for inhibitor screening, several gene cloning and protein purification strategies are presented, including site-directed CA mutants, heterologous CAs from Xenopus oocytes, and native endogenous CAs. The cancer cell-based methods, such as clonogenicity, extracellular acidification, and mass spectrometric gas-analysis are reviewed, confirming nanomolar activities of lead inhibitors in intact cancer cells. Conclusions: Novel CA IX inhibitors are promising derivatives for in vivo explorations. Furthermore, the simultaneous targeting of several proteins involved in proton flux upon tumor acidosis and the disruption of transport metabolons might improve cancer management.


2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Vaida Morkūnaitė ◽  
Lina Baranauskienė ◽  
Asta Zubrienė ◽  
Visvaldas Kairys ◽  
Jekaterina Ivanova ◽  
...  

A series of modified saccharin sulfonamides have been designed as carbonic anhydrase (CA) inhibitors and synthesized. Their binding to CA isoforms I, II, VII, XII, and XIII was measured by the fluorescent thermal shift assay (FTSA) and isothermal titration calorimetry (ITC). Saccharin bound the CAs weakly, exhibiting the affinities of 1–10 mM for four CAs except CA I where binding could not be detected. Several sulfonamide-bearing saccharines exhibited strong affinities of 1–10 nM towards particular CA isoforms. The functional group binding Gibbs free energy additivity maps are presented which may provide insights into the design of compounds with increased affinity towards selected CAs.


2020 ◽  
Vol 27 (3) ◽  
pp. 201-209
Author(s):  
Syed Saqib Ali ◽  
Mohammad Khalid Zia ◽  
Tooba Siddiqui ◽  
Haseeb Ahsan ◽  
Fahim Halim Khan

Background: Ascorbic acid is a classic dietary antioxidant which plays an important role in the body of human beings. It is commonly found in various foods as well as taken as dietary supplement. Objective: The plasma ascorbic acid concentration may range from low, as in chronic or acute oxidative stress to high if delivered intravenously during cancer treatment. Sheep alpha-2- macroglobulin (α2M), a human α2M homologue is a large tetrameric glycoprotein of 630 kDa with antiproteinase activity, found in sheep’s blood. Methods: In the present study, the interaction of ascorbic acid with alpha-2-macroglobulin was explored in the presence of visible light by utilizing various spectroscopic techniques and isothermal titration calorimetry (ITC). Results: UV-vis and fluorescence spectroscopy suggests the formation of a complex between ascorbic acid and α2M apparent by increased absorbance and decreased fluorescence. Secondary structural changes in the α2M were investigated by CD and FT-IR spectroscopy. Our findings suggest the induction of subtle conformational changes in α2M induced by ascorbic acid. Thermodynamics signatures of ascorbic acid and α2M interaction indicate that the binding is an enthalpy-driven process. Conclusion: It is possible that ascorbic acid binds and compromises antiproteinase activity of α2M by inducing changes in the secondary structure of the protein.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mattias Bood ◽  
Anna Wypijewska del Nogal ◽  
Jesper R. Nilsson ◽  
Fredrik Edfeldt ◽  
Anders Dahlén ◽  
...  

AbstractThe aberrant expression of microRNAs (miRs) has been linked to several human diseases. A promising approach for targeting these anomalies is the use of small-molecule inhibitors of miR biogenesis. These inhibitors have the potential to (i) dissect miR mechanisms of action, (ii) discover new drug targets, and (iii) function as new therapeutic agents. Here, we designed Förster resonance energy transfer (FRET)-labeled oligoribonucleotides of the precursor of the oncogenic miR-21 (pre-miR-21) and used them together with a set of aminoglycosides to develop an interbase-FRET assay to detect ligand binding to pre-miRs. Our interbase-FRET assay accurately reports structural changes of the RNA oligonucleotide induced by ligand binding. We demonstrate its application in a rapid, qualitative drug candidate screen by assessing the relative binding affinity between 12 aminoglycoside antibiotics and pre-miR-21. Surface plasmon resonance (SPR) and isothermal titration calorimetry (ITC) were used to validate our new FRET method, and the accuracy of our FRET assay was shown to be similar to the established techniques. With its advantages over SPR and ITC owing to its high sensitivity, small sample size, straightforward technique and the possibility for high-throughput expansion, we envision that our solution-based method can be applied in pre-miRNA–target binding studies.


2020 ◽  
Vol 21 (16) ◽  
pp. 5828
Author(s):  
Katarzyna Łudzik ◽  
Sebastian Woloszczuk ◽  
Wojciech Zając ◽  
Monika Jazdzewska ◽  
Andrey Rogachev ◽  
...  

Inspired by the unusual shapes of the titration curve observed for many surfactants and mixed colloidal systems, we decided to extend the analysis to isothermal titration calorimetric curves (ITC) by paying special attention to potential structural changes in micellar aggregates. In this paper, we used isothermal titration calorimetry in conjunction with Scanning Transmission Electron Microscopy (STEM), Small-Angle Neutron Scattering (SANS) and X-ray Scattering (SAXS) methods support by Monte Carlo and semiempirical quantum chemistry simulations to confirm if the isothermal calorimetric curve shape can reflect micelle transition phenomena. For that purpose, we analysed, from the thermodynamic point of view, a group of cationic gemini surfactants, alkanediyl-α,ω-bis(dimethylalkylammonium) bromides. We proposed the shape of aggregates created by surfactant molecules in aqueous solutions and changes thereof within a wide temperature range. The results provide evidence for the reorganization processes and the relationship (dependence) between the morphology of the created aggregates and the conditions such as temperature, surfactant concentration and spacer chain length which affect the processes.


1896 ◽  
Vol 1 (3) ◽  
pp. 447-481 ◽  
Author(s):  
A. C. Abbott

The deductions that may be drawn from the results of these experiments are as follows: That the normal vital resistance of rabbits to infection by streptococcus pyogenes (erysipelatos) is markedly diminished through the influence of alcohol when given daily to the stage of acute intoxication. That a similar, though by no means so conspicuous, diminution of resistance to infection and intoxication by the bacillus coli communis also occurs in rabbits subjected to the same influences. And that, while in alcoholized rabbits inoculated in various ways with staphylococcus pyogenes aureus, individual instances of lowered resistance are observed, still it is impossible to say from these experiments that in general a marked difference is noticed between alcoholized and non-alcoholized animals as regards infection by this particular organism. It is interesting to note that the results of inoculation of alcoholized rabbits with the erysipelas coccus correspond in a way with clinical observations on human beings addicted to the excessive use of alcohol when infected by this organism. In the course of the work an effort was made to determine if, through the oxidation of alcohol in the tissues to acids of the corresponding chemical group, the increase of susceptibility could be referred to a diminution in the alkalinity of the blood as a result of the presence of such acids. The number of experiments thus far made on this point is too small to justify dogmatic statements, but from what we have gathered there is but little evidence in support of this view. Throughout these experiments, with few exceptions, it will be seen that the alcoholized animals not only showed the effects of the inoculations earlier than did the non-alcoholized rabbits, but in the case of the streptococcus inoculations the lesions produced (formation of miliary abscesses) were much more pronounced than are those that usually follow inoculation with this organism. With regard to the predisposing influence of the alcohol, one is constrained to believe that it is in most cases the result of structural alterations consequent upon its direct action on the tissues, though in a number of the animals no such alteration could be made out by macroscopic examination. I am inclined, however, to the belief, in the light of the work of Berkley and of Friedenwald, done under the direction of Prof. Welch, in the Pathological Laboratory of the Johns Hopkina University, that a closer study of the tissues of these animals would have revealed in all of them structural changes of such a nature as to indicate disturbances of important vital functions of sufficient gravity to fully account for the loss of normal resistance. The conspicuous influence of the alcohol on the gastric mucous membrane in many of these animals, with the consequent disturbance of nutrition, is undoubtedly the explanation of the marked loss in body weight that was observed in many of the animals employed in these experiments. In this light the susceptibility induced by alcohol to excess is somewhat analogous to that induced by starvation, where we see the resistance of animals to particular forms of infection very markedly diminished.


Author(s):  
Vaida Paketurytė ◽  
Asta Zubrienė ◽  
Wen-Yih Chen ◽  
Sandro Keller ◽  
Margarida Bastos ◽  
...  

2003 ◽  
Vol 161 (2) ◽  
pp. 237-241 ◽  
Author(s):  
Danny Köhler ◽  
Christine Ruff ◽  
Edgar Meyhöfer ◽  
Martin Bähler

Myosins are actin-based motors that are generally believed to move by amplifying small structural changes in the core motor domain via a lever arm rotation of the light chain binding domain. However, the lack of a quantitative agreement between observed step sizes and the length of the proposed lever arms from different myosins challenges this view. We analyzed the step size of rat myosin 1d (Myo1d) and surprisingly found that this myosin takes unexpectedly large steps in comparison to other myosins. Engineering the length of the light chain binding domain of rat Myo1d resulted in a linear increase of step size in relation to the putative lever arm length, indicative of a lever arm rotation of the light chain binding domain. The extrapolated pivoting point resided in the same region of the rat Myo1d head domain as in conventional myosins. Therefore, rat Myo1d achieves its larger working stroke by a large calculated ∼90° rotation of the light chain binding domain. These results demonstrate that differences in myosin step sizes are not only controlled by lever arm length, but also by substantial differences in the degree of lever arm rotation.


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