1,721,457 research outputs found
Acipimox inhibits human carbonic anhydrases
Full text linkAcipimox, a nicotinic acid derivative in clinical use for the treatment of hyperlipidaemia, incorporates a free carboxylic acid and an N-oxide moiety, functionalities known to interact with the metalloenzyme carbonic anhydrase (CA, EC 4.2.1.1) and inhibit its activity. Herein we report that acipimox acts as a low micromolar CA inhibitor (CAI) against most human (h) isoforms possessing catalytic activity, hCA I–XIV. By using computational techniques (docking and molecular dynamics simulations), we propose that acipimox coordinates through its carboxylate group to the zinc ion from the enzyme active site cavity, whereas the N-oxide group is hydrogen-bonded to the proton shuttle His residue in some isoforms (hCA I) or to active site Thr or Gln residues in other isoforms (hCA II, III, IV, VII, etc). As some CA isoforms are involved in lipogenesis, these data may be useful for the design of more effective CAIs with antiobesity activity
Phenols and polyphenols as Carbonic anhydrase inhibitors
No full textPhenols are among the largest and most widely distributed groups of secondary metabolites within the plant kingdom. They are implicated in multiple and essential physiological functions. In humans they play an important role as microconstituents of the daily diet, their consumption being considered healthy. The physical and chemical properties of phenolic compounds make these molecules versatile ligands, capable of interacting with a wide range of targets, such as the Carbonic Anhydrases (CAs, EC 4.2.1.1). CAs reversibly catalyze the fundamental reaction of CO2 hydration to bicarbonate and protons in all living organisms, being actively involved in the regulation of a plethora of patho/physiological processes. This review will discuss the most recent advances in the search of naturally occurring phenols and their synthetic derivatives that inhibit the CAs and their mechanisms of action at molecular level. Plant extracts or mixtures are not considered in the present review
An update on natural products with carbonic anhydrase inhibitory activity
No full textCarbonic anhydrases (CAs, EC 4.2.1.1) catalyze the fundamental reaction of CO2 hydration in all living organisms, being actively involved in the regulation of a plethora of patho/physiological processes. They represent a typical example of enzyme convergent evolution, as six genetically unrelated families of such enzymes were described so far. It is more than 70 years that synthetic compounds, mainly sulfonamides, have been used in clinical practice as diuretics and systemic acting antiglaucoma drugs. Recent studies using natural product libraries and isolated constituents from natural sources (such as fungi and plants) have disclosed novel chemotypes possessing carbonic anhydrase inhibition activities. These natural sources offer new opportunities in the search for new and more effective carbonic anhydrase inhibitors, and may serve as new leads for the design and development of future drugs. This review will discuss the most recent advances in the search of naturally occurring products and their synthetic derivatives that inhibit the CAs and their mechanisms of action at molecular level. Plant extracts are not considered in the present review
The Antiepileptic Drug Levetiracetam Inhibits Carbonic Anhydrase: In Vitro and In Silico Studies on Catalytically Active Human Isoforms
No full textSeveral antiepileptic drugs (AEDs) have been found to inhibit human carbonic anhydrases (hCAs), paving the way for repurposing AEDs for the treatment of various diseases, including cancer. Here, the hCAs inhibitory effects of levetiracetam, a highly prescribed AED that does not bear a common zinc-binding group, were investigated in vitro and in silico. Levetiracetam inhibited all tested hCAs, although with a specific profile compared to the reference acetazolamide, with remarkable efficacy against tumor-associated hCA IX and XII. Molecular docking and dynamics (MD) simulations emphasized H-bonding to the Zn(II)-coordinated water as a major anchor point for hCAs, as well as a persistent interaction within the catalytic site of hCA isoforms IX and XII compared to II, which correlates with experimental data. Our results may explain why levetiracetam is also clinically effective as an antitumor agent in patients developing epilepsy as a consequence of brain tumors
Carbonic Anhydrase Inhibitors: Identifying Therapeutic Cancer Agents Through Virtual Screening
Full text linkComputer-aided drug design includes an ensemble of different in silico strategies that represent valuable tools for facilitating the discovery and optimization of novel hit compounds endowed with biological activity toward the desired target proteins. Due to the various pathological implications of carbonic anhydrases (CAs), especially in the development and progression of cancer, molecular modeling techniques have been widely applied for the identification of new CA inhibitors. In this chapter, after providing the reader with a brief introduction to computational methods in drug design, we summarize the results of the main virtual screening (VS) studies that led to the discovery of novel ligands of different CA isoforms, describing the various receptor-based and ligand-based approaches employed. Moreover, we report the results of retrospective analyses in which CAs and their known ligands have been used to validate the performance of various VS methods in hit identification. The present chapter should provide the reader with a panoramic view of the most used and reliable in silico techniques to be applied in the search for novel CA inhibitors
Native mass spectrometry of human carbonic anhydrase I and its inhibitor complexes
Full text linkAbstract: Native mass spectrometry is a potent technique to study and characterize biomacromolecules in their native state. Here, we have applied this method to explore the solution chemistry of human carbonic anhydrase I (hCA I) and its interactions with four different inhibitors, namely three sulfonamide inhibitors (AAZ, MZA, SLC-0111) and the dithiocarbamate derivative of morpholine (DTC). Through high-resolution ESI-Q-TOF measurements, the native state of hCA I and the binding of the above inhibitors were characterized in the molecular detail. Native mass spectrometry was also exploited to assess the direct competition in solution among the various inhibitors in relation to their affinity constants. Additional studies were conducted on the interaction of hCA I with the metallodrug auranofin, under various solution and instrumental conditions. Auranofin is a selective reagent for solvent-accessible free cysteine residues, and its reactivity was analyzed also in the presence of CA inhibitors. Overall, our investigation reveals that native mass spectrometry represents an excellent tool to characterize the solution behavior of carbonic anhydrase. Graphic abstract: [Figure not available: see fulltext.]
Coumarin-pyrazoline Hybrids as Selective Inhibitors of the Tumor-associated Carbonic Anhydrase IX and XII
No full textAim: Human carbonic anhydrase (CA, EC 4.2.1.1) isoforms IX and XII are validated anti-tumor/antimetastatic drug and tumor imaging targets with sulfonamide inhibitors and monoclonal antibodies in clinical development. Coumarins act as isoform-selective inhibitors of these isoforms over the cytosolic and mitochondrial ones. Methods: We report the synthesis and in vitro CA inhibitory evaluation of a large panel of coumarins incorporating pyrazole-1-carboxamide moieties. Compounds were fully characterized before the assessment of their inhibitory activi-ty. A stopped-flow CO2 hydrase assay was performed for the biological test. Results: These coumarins did not inhibit the widespread, off-target isoforms CA I and II (KI >50 μM), but they were sub-micromolar CA IX/XII inhibitors with an interesting selectivity index higher than the reference compound. Selectivity between α-and β-class of CAs was also promising. Conclusion: These compounds may be used as leads for the rational design and development of non-sulfonamide CA IX/XII effective inhibitors
Amine-and amino acid-based compounds as carbonic anhydrase activators
No full textAfter being rather neglected as a research field in the past, carbonic anhydrase activators (CAAs) were undoubtedly demonstrated to be useful in diverse pharmaceutical and industrial applications. They also improved the knowledge of the requirements to selectively interact with a CA isoform over the others and confirmed the catalytic mechanism of this class of compounds. Amino acid and amine derivatives were the most explored in in vitro, in vivo and crystallographic studies as CAAs. Most of them were able to activate human or non-human CA isoforms in the nanomolar range, being proposed as therapeutic and industrial tools. Some isoforms are better activated by amino acids than amines derivatives and the stereochemistry may exert a role. Finally, non-human CAs have been very recently tested for activation studies, paving the way to innovative industrial and environmental applications
Drug Screening in Human Cells by NMR Spectroscopy Allows the Early Assessment of Drug Potency
Full text linkStructure-based drug development is often hampered by the lack of in vivo activity of promising compounds screened in vitro, due to low membrane permeability or poor intracellular binding selectivity. Herein, we show that ligand screening can be performed in living human cells by “intracellular protein-observed” NMR spectroscopy, without requiring enzymatic activity measurements or other cellular assays. Quantitative binding information is obtained by fast, inexpensive 1H NMR experiments, providing intracellular dose- and time-dependent ligand binding curves, from which kinetic and thermodynamic parameters linked to cell permeability and binding affinity and selectivity are obtained. The approach was applied to carbonic anhydrase and, in principle, can be extended to any NMR-observable intracellular target. The results obtained are directly related to the potency of candidate drugs, that is, the required dose. The application of this approach at an early stage of the drug design pipeline could greatly increase the low success rate of modern drug development
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