RESUMO
Carbonic anhydrase (CA) was among the first proteins whose X-ray crystal structure was solved to atomic resolution. CA proteins have essentially the same fold and similar active centers that differ in only several amino acids. Primary sulfonamides are well defined, strong and specific binders of CA. However, minor variations in chemical structure can significantly alter their binding properties. Over 1000 sulfonamides have been designed, synthesized and evaluated to understand the correlations between the structure and thermodynamics of their binding to the human CA isozyme family. Compound binding was determined by several binding assays: fluorescence-based thermal shift assay, stopped-flow enzyme activity inhibition assay, isothermal titration calorimetry and competition assay for enzyme expressed on cancer cell surfaces. All assays have advantages and limitations but are necessary for deeper characterization of these protein-ligand interactions. Here, the concept and importance of intrinsic binding thermodynamics is emphasized and the role of structure-thermodynamics correlations for the novel inhibitors of CA IX is discussed - an isozyme that is overexpressed in solid hypoxic tumors, and thus these inhibitors may serve as anticancer drugs. The abundant structural and thermodynamic data are assembled into the Protein-Ligand Binding Database to understand general protein-ligand recognition principles that could be used in drug discovery.
Assuntos
Anidrases Carbônicas , Isoenzimas , Ligação Proteica , Sulfonamidas , Termodinâmica , Humanos , Cristalografia por Raios X , Anidrases Carbônicas/metabolismo , Anidrases Carbônicas/química , Isoenzimas/metabolismo , Isoenzimas/química , Ligantes , Sulfonamidas/química , Sulfonamidas/farmacologia , Inibidores da Anidrase Carbônica/química , Inibidores da Anidrase Carbônica/farmacologia , Anidrase Carbônica IX/metabolismo , Anidrase Carbônica IX/química , Modelos MolecularesRESUMO
This study explores the binding mechanisms of saccharin derivatives with human carbonic anhydrase IX (hCA IX), an antitumor drug target, with the aim of facilitating the design of potent and selective inhibitors. Through the use of crystallographic analysis, we investigate the structures of hCA IX-saccharin derivative complexes, unveiling their unique binding modes that exhibit both similarities to sulfonamides and distinct orientations of the ligand tail. Our comprehensive structural insights provide information regarding the crucial interactions between the ligands and the protein, shedding light on interactions that dictate inhibitor binding and selectivity. Through a comparative analysis of the binding modes observed in hCA II and hCA IX, isoform-specific interactions are identified, offering promising strategies for the development of isoform-selective inhibitors that specifically target tumor-associated hCA IX. The findings of this study significantly deepen our understanding of the binding mechanisms of hCA inhibitors, laying a solid foundation for the rational design of more effective inhibitors.
Assuntos
Anidrases Carbônicas , Neoplasias , Humanos , Anidrase Carbônica IX/metabolismo , Sacarina/farmacologia , Sacarina/química , Anidrases Carbônicas/metabolismo , Antígenos de Neoplasias/metabolismo , Isoformas de Proteínas/metabolismo , Inibidores da Anidrase Carbônica/química , Relação Estrutura-Atividade , Estrutura MolecularRESUMO
Among the twelve catalytically active carbonic anhydrase isozymes present in the human body, the CAIX is highly overexpressed in various solid tumors. The enzyme acidifies the tumor microenvironment enabling invasion and metastatic processes. Therefore, many attempts have been made to design chemical compounds that would exhibit high affinity and selective binding to CAIX over the remaining eleven catalytically active CA isozymes to limit undesired side effects. It has been postulated that such drugs may have anticancer properties and could be used in tumor treatment. Here we have designed a series of compounds, methyl 5-sulfamoyl-benzoates, which bear a primary sulfonamide group, a well-known marker of CA inhibitors, and determined their affinities for all twelve CA isozymes. Variations of substituents on the benzenesulfonamide ring led to compound 4b, which exhibited an extremely high observed binding affinity to CAIX; the Kd was 0.12 nM. The intrinsic dissociation constant, where the binding-linked protonation reactions have been subtracted, reached 0.08 pM. The compound also exhibited more than 100-fold selectivity over the remaining CA isozymes. The X-ray crystallographic structure of compound 3b bound to CAIX showed the structural position, while several structures of compounds bound to other CA isozymes showed structural reasons for compound selectivity towards CAIX. Since this series of compounds possess physicochemical properties suitable for drugs, they may be developed for anticancer therapeutic purposes.
Assuntos
Benzoatos/farmacologia , Anidrase Carbônica IX/metabolismo , Inibidores da Anidrase Carbônica/farmacologia , Sulfonamidas/farmacologia , Domínio Catalítico/efeitos dos fármacos , Cristalografia por Raios X/métodos , Humanos , Isoenzimas/metabolismo , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Ligação Proteica/fisiologia , Relação Estrutura-Atividade , Termodinâmica , Microambiente Tumoral/efeitos dos fármacos , BenzenossulfonamidasRESUMO
In the design of high-affinity and enzyme isoform-selective inhibitors, we applied an approach of augmenting the substituents attached to the benzenesulfonamide scaffold in three ways, namely, substitutions at the 3,5- or 2,4,6-positions or expansion of the condensed ring system. The increased size of the substituents determined the spatial limitations of the active sites of the 12 catalytically active human carbonic anhydrase (CA) isoforms until no binding was observed because of the inability of the compounds to fit in the active site. This approach led to the discovery of high-affinity and high-selectivity compounds for the anticancer target CA IX and antiobesity target CA VB. The x-ray crystallographic structures of compounds bound to CA IX showed the positions of the bound compounds, whereas computational modeling confirmed that steric clashes prevent the binding of these compounds to other isoforms and thus avoid undesired side effects. Such an approach, based on the Lock-and-Key principle, could be used for the development of enzyme-specific drug candidate compounds.
Assuntos
Inibidores da Anidrase Carbônica , Anidrases Carbônicas , Inibidores Enzimáticos , Inibidores da Anidrase Carbônica/farmacologia , Anidrases Carbônicas/metabolismo , Domínio Catalítico , Inibidores Enzimáticos/farmacologia , Humanos , Isoformas de Proteínas/metabolismo , Relação Estrutura-AtividadeRESUMO
A series of new 3-phenyl-5-aryl-N-(4-sulfamoylphenyl)-4,5-dihydro-1H-pyrazole-1-carboxamide derivatives was designed here, synthesized, and studied for carbonic anhydrase (CAs, EC 4.2.1.1) inhibitory activity against the human (h) isozymes I, II, and VII (cytosolic, off-target isoforms), and IX and XII (anticancer drug targets). Generally, CA I was not effectively inhibited, whereas effective inhibitors were identified against both CAs II (KIs in the range of 5.2-233 nM) and VII (KIs in the range of 2.3-350 nM). Nonetheless, CAs IX and XII were the most susceptible isoforms to this class of inhibitors. In particular, compounds bearing an unsubstituted phenyl ring at the pyrazoline 3 position showed 1.3-1.5 nM KIs against CA IX. In contrast, a subset of derivatives having a 4-halo-phenyl at the same position of the aromatic scaffold even reached subnanomolar KIs against CA XII (0.62-0.99 nM). Docking studies with CA IX and XII were used to shed light on the derivative binding mode driving the preferential inhibition of the tumor-associated CAs. The identified potent and selective CA IX/XII inhibitors are of interest as leads for the development of new anticancer strategies.
Assuntos
Antineoplásicos/farmacologia , Inibidores da Anidrase Carbônica/farmacologia , Anidrases Carbônicas , Pirazóis/farmacologia , Antineoplásicos/química , Sítios de Ligação , Inibidores da Anidrase Carbônica/química , Anidrases Carbônicas/metabolismo , Humanos , Isoenzimas , Modelos Moleculares , Conformação Molecular , Estrutura Molecular , Ligação Proteica , Pirazóis/química , Relação Estrutura-AtividadeRESUMO
By applying an approach of a "ring with two tails", a series of novel inhibitors possessing high-affinity and significant selectivity towards selected carbonic anhydrase (CA) isoforms has been designed. The "ring" consists of 2-chloro/bromo-benzenesulfonamide, where the sulfonamide group is as an anchor coordinating the Zn(II) in the active site of CAs, and halogen atom orients the ring affecting the affinity and selectivity. First "tail" is a substituent containing carbonyl, carboxyl, hydroxyl, ether groups or hydrophilic amide linkage. The second "tail" contains aryl- or alkyl-substituents attached through a sulfanyl or sulfonyl group. Both "tails" are connected to the benzene ring and play a crucial role in selectivity. Varying the substituents, we designed compounds selective for CA VII, CA IX, CA XII, or CA XIV. Since due to binding-linked protonation reactions the binding-ready fractions of the compound and protein are much lower than one, the "intrinsic" affinities were calculated that should be used to study correlations between crystal structures and the thermodynamics of binding for rational drug design. The "intrinsic" affinities together with the intrinsic enthalpies and entropies of binding together with co-crystal structures were used demonstrate structural factors determining major contributions for compound affinity and selectivity.
Assuntos
Inibidores da Anidrase Carbônica/farmacologia , Anidrases Carbônicas/metabolismo , Sulfonamidas/farmacologia , Inibidores da Anidrase Carbônica/síntese química , Inibidores da Anidrase Carbônica/química , Cristalografia por Raios X , Relação Dose-Resposta a Droga , Halogenação , Humanos , Isoenzimas/antagonistas & inibidores , Isoenzimas/metabolismo , Modelos Moleculares , Estrutura Molecular , Relação Estrutura-Atividade , Sulfonamidas/síntese química , Sulfonamidas/química , BenzenossulfonamidasRESUMO
Carbonic anhydrases (CAs, EC 4.2.1.1) catalyze the fundamental reaction of CO2 hydration in all living organisms and are actively involved in the regulation of a plethora of pathological and physiological conditions. A set of new coumarin/ dihydrocoumarin derivatives was here synthesized, characterized, and tested as human CA inhibitors. Their inhibitory activity was evaluated against the cytosolic human isoforms hCA I and II and the transmembrane hCA IX and hCA XII. Two compounds showed potent inhibitory activity against hCA IX, being more active or equipotent with the reference drug acetazolamide. Computational procedures were used to investigate the binding mode of this class of compounds within the active site of hCA IX and XII that are validated as anti-tumor targets.
Assuntos
Inibidores da Anidrase Carbônica/síntese química , Anidrases Carbônicas/química , Cumarínicos/síntese química , Antígenos de Neoplasias/química , Anidrase Carbônica IX/química , Inibidores da Anidrase Carbônica/química , Inibidores da Anidrase Carbônica/farmacologia , Domínio Catalítico , Simulação por Computador , Cumarínicos/química , Cumarínicos/farmacologia , Humanos , Modelos Moleculares , Simulação de Acoplamento Molecular , Estrutura Molecular , Relação Estrutura-AtividadeRESUMO
Twenty-four novel sulfonamide derivatives incorporating dipeptide tails were synthesized by facile acylation reactions of homosulfanilamide through benzotriazole or dicyclohexyl carbodiimide (DCC) mediated coupling reactions. The carbonic anhydrase (CA, EC 4.2.1.1) inhibitory activity of the new compounds was assessed against four human (h) isoforms, hCA I, hCA II, hCA IX and hCA XII. Most of the synthesized compounds showed good in vitro carbonic anhydrase inhibitory properties, with inhibition constants in the low nanomolar range. Particularly, the new dipeptide-sulfonamide conjugates incorporating Ala, Phe and Met in the dipeptide sequence, showed the most effective inhibitory activity against to CA IX and XII.
Assuntos
Inibidores da Anidrase Carbônica/química , Dipeptídeos/química , Sulfonamidas/química , Antígenos de Neoplasias , Anidrase Carbônica I/antagonistas & inibidores , Anidrase Carbônica II/antagonistas & inibidores , Anidrase Carbônica IX/antagonistas & inibidores , Inibidores da Anidrase Carbônica/síntese química , Dipeptídeos/síntese química , Humanos , Isoenzimas/antagonistas & inibidores , Sulfonamidas/síntese químicaRESUMO
Human carbonic anhydrase (CA) IX has emerged as a promising anticancer target and a diagnostic biomarker for solid hypoxic tumors. Novel fluorinated CA IX inhibitors exhibited up to 50 pM affinity towards the recombinant human CA IX, selectivity over other CAs, and direct binding to Zn(II) in the active site of CA IX inducing novel conformational changes as determined by X-ray crystallography. Mass spectrometric gas-analysis confirmed the CA IX-based mechanism of the inhibitors in a CRISPR/Cas9-mediated CA IX knockout in HeLa cells. Hypoxia-induced extracellular acidification was significantly reduced in HeLa, H460, MDA-MB-231, and A549 cells exposed to the compounds, with the IC50 values up to 1.29 nM. A decreased clonogenic survival was observed when hypoxic H460 3D spheroids were incubated with our lead compound. These novel compounds are therefore promising agents for CA IX-specific therapy.
RESUMO
In this study, new 4-[3-(aryl)-5-substitutedphenyl-4,5-dihydro-1H-pyrazole-1-yl]benzensulfonamides (19-36) were synthesized and evaluated their cytotoxic/anticancer and CA inhibitory effects. According to results obtained, the compounds 34 (4-[5-(2,3,4-trimethoxyphenyl)-3-(thiophen-2-yl)-4,5-dihydro-1H-pyrazole-1-yl] benzensulfonamide, Potency-Selectivity Expression (PSE)â¯=â¯141) and 36 (4-[5-(3,4,5-trimethoxyphenyl)-3-(thiophen-2-yl)-4,5-dihydro-1H-pyrazole-1-yl]benzensulfonamide, PSEâ¯=â¯54.5) were found the leader anticancer compounds with the highest PSE values. In CA inhibitory studies, the compounds 36 and 24 (4-[5-(3,4,5-trimethoxyphenyl)-3-(4-fluorophenyl)-4,5-dihydro-1H-pyrazole-1-yl]benzensulfonamide) were found the leader CA inhibitors depending on selectivity ratios. The compound 36 was a selective inhibitor of hCA XII isoenzyme (hCA I/hCA XIIâ¯=â¯1250 and hCA II/hCA XIIâ¯=â¯224) while the compound 24 was a selective inhibitor of hCA IX isoenzyme (hCA I/hCA IXâ¯=â¯161 and hCA II/hCA IXâ¯=â¯177). The compounds 24, 34, and 36 can be considered to develop new anticancer drug candidates.
Assuntos
Antineoplásicos/farmacologia , Anidrase Carbônica IX/antagonistas & inibidores , Inibidores da Anidrase Carbônica/farmacologia , Anidrases Carbônicas/metabolismo , Pirazóis/farmacologia , Sulfonamidas/farmacologia , Antígenos de Neoplasias/metabolismo , Antineoplásicos/síntese química , Antineoplásicos/química , Anidrase Carbônica IX/metabolismo , Inibidores da Anidrase Carbônica/síntese química , Inibidores da Anidrase Carbônica/química , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Isoenzimas/antagonistas & inibidores , Isoenzimas/metabolismo , Estrutura Molecular , Pirazóis/síntese química , Pirazóis/química , Relação Estrutura-Atividade , Sulfonamidas/síntese química , Sulfonamidas/químicaRESUMO
A series of N-acylbenzenesulfonamide dihydro-1,3,4-oxadiazole hybrids (EMAC8000a-m) was designed and synthesized with the aim to target tumor associated carbonic anhydrase (hCA) isoforms IX and XII. Most of the compounds were selective inhibitors of the tumor associated hCA XII. Moreover, resolution of EMAC8000d racemic mixture led to the isolation of the levorotatory eutomer exhibiting an increase of hCA XII inhibition potency and selectivity with respect to hCA II. Computational studies corroborated these data. Overall our data indicate that both substitution pattern and stereochemistry of dihydro-1,3,4-oxadiazole could be considered as key factors to determine activity and selectivity toward hCA isozymes. These results can provide further indication for the design and optimization of selective hCA inhibitors.
RESUMO
A new chemotype with carbonic anhydrase (CA, EC 4.2.1.1) inhibitory action has been discovered, the homo-sulfocoumarins (3H-1,2-benzoxathiepine 2,2-dioxides) which have been designed considering the (sulfo)coumarins as lead molecules. An original synthetic strategy of a panel of such derivatives led to compounds with a unique inhibitory profile and very high selectivity for the inhibition of the tumour associated (CA IX/XII) over the cytosolic (CA I/II) isoforms. Although the CA inhibition mechanism with these new compounds is unknown for the moment, we hypothesize that it may be similar to that of the sulfocoumarins, i.e. hydrolysis to the corresponding sulfonic acids which thereafter anchor to the zinc-coordinated water molecule within the enzyme active site.
Assuntos
Inibidores da Anidrase Carbônica/farmacologia , Anidrases Carbônicas/metabolismo , Óxidos S-Cíclicos/farmacologia , Inibidores da Anidrase Carbônica/síntese química , Inibidores da Anidrase Carbônica/química , Óxidos S-Cíclicos/síntese química , Óxidos S-Cíclicos/química , Relação Dose-Resposta a Droga , Humanos , Estrutura Molecular , Relação Estrutura-AtividadeRESUMO
A series of N-substituted saccharins incorporating aryl, alkyl and alkynyl moieties, as well as some ring opened derivatives were prepared and investigated as inhibitors of the metalloenzyme carbonic anhydrase (CA, EC 4.2.1.1). The widespread cytosolic isoforms CA I and II were not inhibited by these sulfonamides whereas transmembrane, tumor-associated ones were effectively inhibited, with KIs in the range of 22.1-481nM for CA IX and of 3.9-245nM for hCA XII. Although the inhibition mechanism of these tertiary/secondary sulfonamides is unknown for the moment, the good efficacy and especially selectivity for the inhibition of the tumor-associated over the cytosolic, widespread isoforms, make these derivatives of considerable interest as enzyme inhibitors with various pharmacologic applications.
Assuntos
Anidrase Carbônica IX/antagonistas & inibidores , Inibidores da Anidrase Carbônica/farmacologia , Anidrases Carbônicas/metabolismo , Sacarina/farmacologia , Antígenos de Neoplasias/metabolismo , Anidrase Carbônica IX/metabolismo , Inibidores da Anidrase Carbônica/síntese química , Inibidores da Anidrase Carbônica/química , Relação Dose-Resposta a Droga , Humanos , Estrutura Molecular , Sacarina/síntese química , Sacarina/química , Relação Estrutura-AtividadeRESUMO
A series of 5-substituted-benzylsulfanyl-thiophene-2-sulfonamides was prepared by reacting 5-bromo-thiophene-2-sulfonamide with 5-substituted-benzyl mercaptans. The new compounds were investigated as carbonic anhydrase (CA, EC 4.2.1.1) inhibitors. The cytosolic human (h) isoforms hCA I was poorly inhibited by the new sulfonamides (KIs in the range of 683-4250nM), whereas hCA II, and the transmembrane, tumor associated isoforms hCA IX and XII were effectively inhibited in the subnanomolar-nanomolar range. A high resolution X-ray crystal structure of the adduct of hCA II with one of the new sulfonamides allowed us to rationalize the excellent inhibitory activity of these heterocyclic sulfonamides.
Assuntos
Inibidores da Anidrase Carbônica/farmacologia , Anidrases Carbônicas/metabolismo , Sulfonamidas/farmacologia , Tiofenos/farmacologia , Inibidores da Anidrase Carbônica/síntese química , Inibidores da Anidrase Carbônica/química , Cristalografia por Raios X , Relação Dose-Resposta a Droga , Humanos , Modelos Moleculares , Estrutura Molecular , Soluções , Relação Estrutura-Atividade , Sulfonamidas/síntese química , Sulfonamidas/química , Tiofenos/síntese química , Tiofenos/químicaRESUMO
2-Aminoquinazolin-4(3H)-ones were identified as a novel class of malaria digestive vacuole plasmepsin inhibitors by using NMR-based fragment screening against Plm II. Initial fragment hit optimization led to a submicromolar inhibitor, which was cocrystallized with Plm II to produce an X-ray structure of the complex. The structure showed that 2-aminoquinazolin-4(3H)-ones bind to the open flap conformation of the enzyme and provided clues to target the flap pocket. Further improvement in potency was achieved via introduction of hydrophobic substituents occupying the flap pocket. Most of the 2-aminoquinazolin-4(3H)-one based inhibitors show a similar activity against digestive Plms I, II, and IV and >10-fold selectivity versus CatD, although varying the flap pocket substituent led to one Plm IV selective inhibitor. In cell-based assays, the compounds show growth inhibition of Plasmodium falciparum 3D7 with IC50 â¼ 1 µM. Together, these results suggest 2-aminoquinazolin-4(3H)-ones as perspective leads for future development of an antimalarial agent.
Assuntos
Antimaláricos/síntese química , Antimaláricos/farmacologia , Ácido Aspártico Endopeptidases/antagonistas & inibidores , Quinazolinas/síntese química , Quinazolinas/farmacologia , Células 3T3 , Animais , Sobrevivência Celular/efeitos dos fármacos , Cristalografia por Raios X , Malária/tratamento farmacológico , Malária/parasitologia , Camundongos , Modelos Moleculares , Plasmodium falciparum/efeitos dos fármacos , Relação Estrutura-AtividadeRESUMO
Plasmepsin II (PMII) is one of the ten plasmepsins (PMs) identified in the genome of Plasmodium falciparum, the causative agent of the most severe and deadliest form of malaria. Owing to the emergence of P. falciparum strains that are resistant to current antimalarial agents such as chloroquine and sulfadoxine/pyrimethamine, there is a constant pressure to find new and lasting chemotherapeutic drug therapies. Previously, the crystal structure of PMII in complex with NU655, a potent antimalarial hydroxyethylamine-based inhibitor, and the design of new compounds based on it have been reported. In the current study, two of these newly designed hydroxyethylamine-based inhibitors, PG418 and PG394, were cocrystallized with PMII and their structures were solved, analyzed and compared with that of the PMII-NU655 complex. Structural analysis of the PMII-PG418 complex revealed that the flap loop can adopt a fully closed conformation, stabilized by interactions with the inhibitor, and a fully open conformation, causing an overall expansion in the active-site cavity, which in turn causes unstable binding of the inhibitor. PG418 also stabilizes the flexible loop Gln275-Met286 of another monomer in the asymmetric unit of PMII, which is disordered in the PMII-NU655 complex structure. The crystal structure of PMII in complex with the inhibitor PG418 demonstrates the conformational flexibility of the active-site cavity of the plasmepsins. The interactions of the different moieties in the P1' position of PG418 and PG394 with Thr217 have to be taken into account in the design of new potent plasmepsin inhibitors.
Assuntos
Ácido Aspártico Endopeptidases/química , Benzamidas/farmacologia , Inibidores Enzimáticos/farmacologia , Etanolaminas/farmacologia , Plasmodium falciparum/metabolismo , Propanolaminas/farmacologia , Proteínas de Protozoários/química , Antimaláricos/química , Antimaláricos/farmacologia , Ácido Aspártico Endopeptidases/antagonistas & inibidores , Domínio Catalítico , Catepsinas/antagonistas & inibidores , Cristalografia por Raios X , Dimerização , Inibidores Enzimáticos/química , Humanos , Ligantes , Plasmodium falciparum/efeitos dos fármacos , Estrutura Secundária de Proteína , Proteínas de Protozoários/antagonistas & inibidoresRESUMO
Human carbonic anhydrase IX (CA IX) is overexpressed in a number of solid tumors and is considered to be a marker for cellular hypoxia that it is not produced in most normal tissues. CA IX contributes to the acidification of the extracellular matrix, which, in turn, favors tumor growth and metastasis. Therefore, CA IX is considered to be a promising anti-cancer drug target. However, the ability to specifically target CA IX is challenging due to the fact that the human genome encodes 15 different carbonic anhydrase isoforms that have a high degree of homology. Furthermore, structure-based drug design of CA IX inhibitors so far has been largely unsuccessful due to technical difficulties regarding the expression and crystallization of the enzyme. Currently, only one baculovirus-produced CA IX structure in complex with a nonspecific CA inhibitor, acetazolamide, is available in Protein Data Bank. We have developed an efficient system for the production of the catalytic domain of CA IX in methylotrophic yeast Pichia pastoris. The produced protein can be easily crystallized in the presence of inhibitors, as we have demonstrated for several 2-thiophene-sulfonamide compounds. We have also observed significant differences in the binding mode of chemically identical compounds to CA IX and CA II, which can be further exploited in the design of CA IX-specific inhibitors.
Assuntos
Antígenos de Neoplasias/química , Anidrases Carbônicas/química , Neoplasias/enzimologia , Acetazolamida/farmacologia , Antígenos de Neoplasias/biossíntese , Antineoplásicos/farmacologia , Baculoviridae/metabolismo , Anidrase Carbônica IX , Inibidores da Anidrase Carbônica/farmacologia , Anidrases Carbônicas/biossíntese , Clonagem Molecular , Cristalização , Bases de Dados de Proteínas , Humanos , Isoenzimas , Modelos Moleculares , Pichia/enzimologia , Relação Estrutura-Atividade , Especificidade por Substrato , Difração de Raios XRESUMO
1-N-Alkylated-6-sulfamoyl saccharin derivatives were prepared and assayed as carbonic anhydrase inhibitors (CAIs). During X-ray crystallographic experiments an unexpected hydrolysis of the isothiazole ring was evidenced which allowed us to prepare highly potent enzyme inhibitors with selectivity for some isoforms with medical applications.
Assuntos
Inibidores da Anidrase Carbônica/farmacologia , Anidrases Carbônicas/química , Anidrases Carbônicas/metabolismo , Desenho de Fármacos , Cristalografia por Raios X , Humanos , Isoenzimas/antagonistas & inibidores , Isoenzimas/química , Modelos Moleculares , Conformação ProteicaRESUMO
Antimalarial hit 1 SR (TCMDC-134674) identified in a GlaxoSmithKline cell based screening campaign was evaluated for inhibitory activity against the digestive vacuole plasmepsins (Plm I, II, and IV). It was found to be a potent Plm IV inhibitor with no selectivity over Cathepsin D. A cocrystal structure of 1 SR bound to Plm II was solved, providing structural insight for the design of more potent and selective analogues. Structure-guided optimization led to the identification of structurally simplified analogues 17 and 18 as low nanomolar inhibitors of both, plasmepsin Plm IV activity and P. falciparum growth in erythrocytes.
RESUMO
γ-Butyrobetaine hydroxylase (BBOX) catalyzes the conversion of gamma butyrobetaine (GBB) to l-carnitine, which is involved in the generation of metabolic energy from long-chain fatty acids. BBOX inhibitor 3-(1,1,1-trimethylhydrazin-1-ium-2-yl)propanoate (mildronate), which is an approved, clinically used cardioprotective drug, is a relatively poor BBOX inhibitor and requires high daily doses. In this paper we describe the design, synthesis, and properties of 51 compounds, which include both GBB and mildronate analogues. We have discovered novel BBOX inhibitors with improved IC50 values; the best examples are in the nanomolar range and about 2 orders of magnitude better when compared to mildronate. For six inhibitors, crystal structures in complex with BBOX have been solved to explain their activities and pave the way for further inhibitor design.