Methyl 2-Halo-4-Substituted-5-Sulfamoyl-Benzoates as High Affinity and Selective Inhibitors of Carbonic Anhydrase IX

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 chemica...

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Main Authors: Audrius Zakšauskas, Edita Čapkauskaitė, Vaida Paketurytė-Latvė, Alexey Smirnov, Janis Leitans, Andris Kazaks, Elviss Dvinskis, Laimonas Stančaitis, Aurelija Mickevičiūtė, Jelena Jachno, Linas Jezepčikas, Vaida Linkuvienė, Andrius Sakalauskas, Elena Manakova, Saulius Gražulis, Jurgita Matulienė, Kaspars Tars, Daumantas Matulis
Format: Article
Language:English
Published: MDPI AG 2021-12-01
Series:International Journal of Molecular Sciences
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Online Access:https://www.mdpi.com/1422-0067/23/1/130
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Summary: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 <b>4b</b>, which exhibited an extremely high <i>observed</i> binding affinity to CAIX; the <i>K<sub>d</sub></i> was 0.12 nM. The <i>intrinsic</i> 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 <b>3b</b> 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.
ISSN:1661-6596
1422-0067