Acetazolamide-based fungal chitinase inhibitors

Schüttelkopf, Alexander W.; Gros, Ludovic; Blair, D.E.; Frearson, Julie A.; Aalten, Daan M. F. van; Gilbert, Ian H.

doi:10.1016/j.bmc.2010.09.062

Cited by 46 publications

(46 citation statements)

References 33 publications

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“…Different phases of biofilm (8,12, and 24 h), with or without azetazolamide (128 mg/liter; Sigma), a chitinase inhibitor (36), were formed at 37°C either in microtiter plates or in tissue culture flasks as described above. The quantity of eDNA within the ECM was measured using a microplate fluorescence assay (MFA) with a DNA-binding dye (SYBR green I) as previously described (37).…”

Section: Methodsmentioning

confidence: 99%

Extracellular DNA Release Acts as an Antifungal Resistance Mechanism in Mature Aspergillus fumigatus Biofilms

et al. 2013

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dAspergillus fumigatus has been shown to form biofilms that are associated with adaptive antifungal resistance mechanisms. These include multidrug efflux pumps, heat shock proteins, and extracellular matrix (ECM). ECM is a key structural and protective component of microbial biofilms and in bacteria has been shown to contain extracellular DNA (eDNA). We therefore hypothesized that A. fumigatus biofilms also possess eDNA as part of the ECM, conferring a functional role. Fluorescence microscopy and quantitative PCR analyses demonstrated the presence of eDNA, which was released phase dependently (8 < 12 < 24 < 48 h). Random amplification of polymorphic DNA (RAPD) PCR showed that eDNA was identical to genomic DNA. Biofilm architectural integrity was destabilized by DNase treatment. Biochemical and transcriptional analyses showed that chitinase activity and mRNA levels of chitinase, a marker of autolysis, were significantly upregulated as the biofilm matured and that inhibition of chitinases affected biofilm growth and stability, indicating mechanistically that autolysis was possibly involved. Finally, using checkerboard assays, it was shown that combinational treatment of biofilms with DNase plus amphotericin B and caspofungin significantly improved antifungal susceptibility. Collectively, these data show that eDNA is an important structural component of A. fumigatus ECM that is released through autolysis, which is important for protection from environmental stresses, including antifungal therapy.

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Section: Methodsmentioning

confidence: 99%

Extracellular DNA Release Acts as an Antifungal Resistance Mechanism in Mature Aspergillus fumigatus Biofilms

et al. 2013

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“…Chitinase has been suggested to play an essential role in the remodeling of the fungal cell wall and hence can serve as an important target for drug design and development. Consistent with this thought, a co-crystal structure of Af ChiA1 with acetazolamide has been used to explore the identification of inhibitors of chitinase as new antifungal agents [101]. There has also been a report of a screening-based discovery of chitinase inhibitors as antifungal agents against Aspergillus fumigatus [102].…”

Section: Fungal Cell Wall As a Drug Development Targetmentioning

confidence: 99%

The Mechanistic Targets of Antifungal Agents: An Overview

Mazu¹,

Bricker²,

Flores‐Rozas³

et al. 2016

MRMC

168

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Pathogenic fungi are a major causative group for opportunistic infections (OIs). AIDS patients and other immunocompromised individuals are at risk for OIs, which if not treated appropriately, contribute to the mortality associated with their conditions. Several studies have indicated that the majority of HIV-positive patients contract fungal infections throughout the course of their disease. Similar observations have been made regarding the increased frequency of bone marrow and organ transplants, the use of antineoplastic agents, the excessive use of antibiotics, and the prolonged use of corticosteroids among others. In addition, several pathogenic fungi have developed resistance to current drugs. Together these have conspired to spur a need for developing new treatment options for OIs. To aid this effort, this article reviews the biological targets of current and emerging drugs and agents that act through these targets for the treatment of opportunistic fungal infections.

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“…The crystal structures of chitinases with one single GH18 domain have been extensively studied in archaea (Tsuji et al, 2010), bacteria (Perrakis et al, 1994;van Aalten et al, 2000;Songsiriritthigul et al, 2008;Hsieh et al, 2010;Busby et al, 2012;Payne et al, 2012;Madhuprakash et al, 2013;Malecki et al, 2013;Ü stok et al, 2015;Itoh et al, 2016), fungi (Hollis et al, 2000;Rao et al, 2005;Hurtado-Guerrero & van Aalten, 2007;Schü ttelkopf et al, 2010;Yang et al, 2010), plants (Terwisscha van Scheltinga et al, 1994;Cavada et al, 2006;Ohnuma, Numata, Osawa, Mizuhara, Lampela et al, 2011;Ohnuma, Numata, Osawa, Mizuhara, Vå rum et al, 2011;Kitaoku et al, 2015;Masuda et al, 2015;Umemoto et al, 2015), insects Liu et al, 2017) and humans (Fusetti et al, 2002;Olland et al, 2009). Although the overall structure of these GH18 domains is a (/) 8 -barrel with a substrate-binding cleft on the top side, they can be differentiated by the shapes of the substrate-binding clefts and the presence or absence of insertion domains.…”

Section: Introductionmentioning

confidence: 99%

The deduced role of a chitinase containing two nonsynergistic catalytic domains

Liu

Zhu

Wang

et al. 2018

Acta Cryst Sect D Struct Biol

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The glycoside hydrolase family 18 chitinases degrade or alter chitin. Multiple catalytic domains in a glycoside hydrolase family 18 chitinase function synergistically during chitin degradation. Here, an insect group III chitinase from the agricultural pest Ostrinia furnacalis (OfChtIII) is revealed to be an arthropod-conserved chitinase that contains two nonsynergistic GH18 domains according to its catalytic properties. Both GH18 domains are active towards single-chained chitin substrates, but are inactive towards insoluble chitin substrates. The crystal structures of each unbound GH18 domain, as well as of GH18 domains complexed with hexa-N-acetyl-chitohexaose or penta-N-acetylchitopentaose, suggest that the two GH18 domains possess endo-specific activities. Physiological data indicated that the developmental stage-dependent gene-expression pattern of OfChtIII was the same as that of the chitin synthase OfChsA but significantly different from that of the chitinase OfChtI, which is indispensable for cuticular chitin degradation. Additionally, immunological staining indicated that OfChtIII was co-localized with OfChsA. Thus, OfChtIII is most likely to be involved in the chitin-synthesis pathway.

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Acetazolamide-based fungal chitinase inhibitors

Abstract: Graphical abstract

Cited by 46 publications

References 33 publications

Extracellular DNA Release Acts as an Antifungal Resistance Mechanism in Mature Aspergillus fumigatus Biofilms

Extracellular DNA Release Acts as an Antifungal Resistance Mechanism in Mature Aspergillus fumigatus Biofilms

The Mechanistic Targets of Antifungal Agents: An Overview

The deduced role of a chitinase containing two nonsynergistic catalytic domains

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