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Tea Lanišnik Rižner - One of the best experts on this subject based on the ideXlab platform.
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CYP53A15 of Cochliobolus lunatus, a target for natural antifungal compounds.
Journal of medicinal chemistry, 2008Co-Authors: Barbara Podobnik, Tea Lanišnik Rižner, Damjana Rozman, Jure Stojan, Ljerka Lah, Nada Kraševec, Matej Seliškar, Radovan KomelAbstract:A novel cytochrome P450, CYP53A15, was identified in the pathogenic filamentous ascomycete Cochliobolus lunatus. The protein, classified into the CYP53 family, was capable of para hydroxylation of benzoate. Benzoate is a key intermediate in the metabolism of aromatic compounds in fungi and yet basically toxic to the organism. To guide functional analyses, protein structure was predicted by homology modeling. Since many naturally occurring antifungal phenolic compounds are structurally similar to CYP53A15 substrates, we tested their putative binding into the active site of CYP53A15. Some of these compounds inhibited CYP53A15. Increased antifungal activity was observed when tested in the presence of benzoate. Some results suggest that CYP53A15 O-demethylation activity is important in detoxification of other antifungal substances. With the design of potent inhibitors, CYP53 enzymes could serve as alternative antifungal drug targets.
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New inhibitors of fungal 17β-hydroxysteroid dehydrogenase based on the [1,5]-benzodiazepine scaffold
Journal of enzyme inhibition and medicinal chemistry, 2007Co-Authors: Matej Živec, Tea Lanišnik Rižner, Matej Sova, Mojca Brunskole, Roman Lenarsic, Stanislav GobecAbstract:The synthesis and activity of a new series of non-steroidal inhibitors of 17β-hydroxysteroid dehydrogenase that are based on a 1,5-benzodiazepine scaffold are presented. Their inhibitory potential was screened against 17β-hydroxysteroid dehydrogenase from the fungus Cochliobolus lunatus (17β-HSDcl), a model enzyme of the short-chain dehydrogenase/reductase superfamily. Some of these compounds are potent inhibitors of 17β-HSDcl activity, with IC50 values in the low micromolar range and represent promising lead compounds that should be further developed and investigated as inhibitors of human 17β-HSD isoforms, which are the enzymes associated with the development of many hormone-dependent and neuronal diseases.
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conformational stability of 17β hydroxysteroid dehydrogenase from the fungus Cochliobolus lunatus
FEBS Journal, 2006Co-Authors: Nataša Poklar Ulrih, Tea Lanišnik RižnerAbstract:The functional activities of proteins are closely related to their molecular structure and understanding their structure–function relationships remains one of the intriguing problems of molecular biology. We investigated structural changes in 17β-hydroxysteroid dehydrogenase from the fungus Cochliobolus lunatus (17β-HSDcl) induced by pH, temperature, salt, urea, guanidine hydrochloride, and coenzyme NADPH binding. At 25 °C and within the relatively narrow pH range of 7.0–9.0, 17β-HSDcl exists in its native conformation as a dimer. This native conformation is thermally stable up to 40 °C in this pH range. At 25 °C and pH 2.0 in the presence of 150–300 mm NaCl, 17β-HSDcl forms soluble aggregates enriched in α-helical and β-sheet structures. At higher temperatures and NaCl concentrations, these soluble aggregates start to precipitate. The denaturants urea and guanidine hydrochloride unfold 17β-HSDcl at concentrations of 1.2 and 0.4 m, respectively. Binding of the coenzyme NADPH to 17β-HSDcl causes local structural changes that do not significantly affect the thermal stability of this protein.
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Conformational stability of 17β‐hydroxysteroid dehydrogenase from the fungus Cochliobolus lunatus
The FEBS journal, 2006Co-Authors: Nataša Poklar Ulrih, Tea Lanišnik RižnerAbstract:The functional activities of proteins are closely related to their molecular structure and understanding their structure–function relationships remains one of the intriguing problems of molecular biology. We investigated structural changes in 17β-hydroxysteroid dehydrogenase from the fungus Cochliobolus lunatus (17β-HSDcl) induced by pH, temperature, salt, urea, guanidine hydrochloride, and coenzyme NADPH binding. At 25 °C and within the relatively narrow pH range of 7.0–9.0, 17β-HSDcl exists in its native conformation as a dimer. This native conformation is thermally stable up to 40 °C in this pH range. At 25 °C and pH 2.0 in the presence of 150–300 mm NaCl, 17β-HSDcl forms soluble aggregates enriched in α-helical and β-sheet structures. At higher temperatures and NaCl concentrations, these soluble aggregates start to precipitate. The denaturants urea and guanidine hydrochloride unfold 17β-HSDcl at concentrations of 1.2 and 0.4 m, respectively. Binding of the coenzyme NADPH to 17β-HSDcl causes local structural changes that do not significantly affect the thermal stability of this protein.
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Dimerization and enzymatic activity of fungal 17β-hydroxysteroid dehydrogenase from the short-chain dehydrogenase/reductase superfamily
BMC biochemistry, 2005Co-Authors: Katja Kristan, Jerzy Adamski, Jure Stojan, Dominga Deluca, Tea Lanišnik RižnerAbstract:Background 17β-hydroxysteroid dehydrogenase from the fungus Cochliobolus lunatus (17β-HSDcl) is a member of the short-chain dehydrogenase/reductase (SDR) superfamily. SDR proteins usually function as dimers or tetramers and 17β-HSDcl is also a homodimer under native conditions.
Chang-yun Wang - One of the best experts on this subject based on the ideXlab platform.
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Annular oxygenation and rearrangement products of cryptotanshinone by biotransformation with marine-derived fungi Cochliobolus lunatus and Aspergillus terreus.
Bioorganic chemistry, 2020Co-Authors: Qin-yu Meng, Chang-lun Shao, Xiao-hui Shi, Ya-hui Zhang, Peng Zhang, Chang-yun WangAbstract:Abstract Structural modification of natural products by biotransformation with fungi is an attractive tool to obtain novel bioactive derivatives. In the present study, cryptotanshinone (1), a quinoid abietane diterpene from traditional Chinese medicine Salvia miltiorrhiza (Danshen), was transformed by two marine-derived fungi. By using Cochliobolus lunatus TA26-46, one new oxygenated and rearranged product (2), containing a 5,6-dihydropyrano[4,3-b]chromene moiety, together with one known metabolite (10), were obtained from the converted broth of cryptotanshinone (1) with the isolated yields of 1.0% and 2.1%, respectively. While, under the action of Aspergillus terreus RA2905, seven new transformation products (3–9) as well as 10 with the fragments of 2-methylpropan-1-ol and oxygenated p-benzoquinone were produced and obtained with the isolated yields of 0.1%–1.3%. The structures of the new compounds were elucidated by comprehensive spectroscopic analysis including High Resolution Electrospray Ionization Mass Spectroscopy (HRESIMS), Nuclear Magnetic Resonance (NMR) and Electronic Circular Dichroism (ECD). The metabolic pathways of cryptotanshinone by these two fungi were presumed to be the opening and rearrangement of furan ring, and/or oxygenation of cyclohexane ring. Cryptotanshinone (1) and its metabolites displayed anti-inflammatory activities against NO production in LPS-stimulated BV-2 cells and antibacterial activities towards methicillin-resistant Staphylococcus aureus. These findings revealed the potential of marine fungi to transform the structures of natural products by biotransformation.
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Co-cultivation With 5-Azacytidine Induced New Metabolites From the Zoanthid-Derived Fungus Cochliobolus lunatus.
Frontiers in chemistry, 2019Co-Authors: Xiao-hui Shi, Chang-lun Shao, Ya-hui Zhang, Kai-xian Chen, Yue-wei Guo, Chang-yun WangAbstract:The zoanthid-derived fungus Cochliobolus lunatus (TA26-46) has been proven to be a source of bioactive 14-membered resorcylic acid lactones (RALs). In the present study, chemical epigenetic manipulation was applied to this fungal strain with a DNA methyltransferase inhibitor resulting in the significant changes of the secondary metabolites. Cultivation of C. lunatus (TA26-46) with 10 μM 5-azacytidine in Czapek-Dox liquid medium led to the isolation of new types of metabolites, including two α-pyrones, cochliobopyrones A (1) and B (2), along with three isocoumarins (3-5) and one chromone (6). The planar structures of the new compounds (1-2) were elucidated by comprehensive analyses of NMR and HRESIMS data. Their challenging relative configurations were established by a combination of acetonide reaction, coupling constants and NOESY correlations analysis, and DP4+ probability calculation. Their absolute configurations were determined by comparing with the ECD calculation data of the fragment molecules, 6-(1,2-dihydroxypropyl)-4-methoxy-2H-pyran-2-ones. It is the first time to obtain α-pyrone compounds with the epoxy ring or bromine atom on the seven-numbered side chain. It could be concluded that chemical epigenetic agents could induce C. lunatus to produce new types of secondary metabolites differing from its original products (RALs).
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Cochliomycin G, a 14-membered resorcylic acid lactone from a marine-derived fungus Cochliobolus lunatus.
Natural product research, 2019Co-Authors: Xiao-jia Xue, Chang-yun Wang, Chang-lun ShaoAbstract:Cochliomycin G (1), a new 14-membered resorcylic acid lactone, together with six known analogues (2−7), was isolated from the culture broth of a marine-derived fungus Cochliobolus lunatus. The plan...
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DNA Methyltransferase Inhibitor Induced Fungal Biosynthetic Products: Diethylene Glycol Phthalate Ester Oligomers from the Marine-Derived Fungus Cochliobolus lunatus
Marine biotechnology (New York N.Y.), 2016Co-Authors: Min Chen, Wei Zhang, Chang-lun Shao, Zhen-ming Chi, Chang-yun WangAbstract:Chemical epigenetic manipulation was applied to the marine-derived fungus Cochliobolus lunatus (TA26–46) with a DNA methyltransferase inhibitor resulting in the significant changes of the secondary metabolites. Cultivation of C. lunatus (TA26–46) with 5-azacytidine led to the isolation of seven new diethylene glycol phthalate esters, cochphthesters A−G (1−6, 10), along with four known analogues (7−9, 11). Their structures were determined by extensive NMR spectroscopic spectra as well as MS data. Compounds 2−6 and 8−11, characterized by the cross-polymerization of phthalate across diethylene glycol via ester bonds, represent the first example of naturally occurring phthalate ester oligomers.
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Antifouling and Fungicidal Resorcylic Acid Lactones from the Sea Anemone-Derived Fungus Cochliobolus lunatus.
Journal of agricultural and food chemistry, 2014Co-Authors: Qing-ai Liu, Min Chen, Chang-lun Shao, Mathias Blum, Li-she Gan, Kai-ling Wang, Chang-yun WangAbstract:Three new 14-membered resorcylic acid lactones, cochliomycins D-F, 1-3, and eight known analogues, 4-11, were isolated from the sea anemone-derived fungus Cochliobolus lunatus. Compounds 1-4 are diastereomers differing from each other by the absolute configurations of the 4',5'-diol chiral centers. The absolute configurations of 1-4 were established by the CD exciton chirality method and TDDFT ECD calculations. In antifouling assays, 1, 3-6, and 6a exhibited potent antifouling activities against the larval settlement of the barnacle Balanus amphitrite at nontoxic concentrations, with EC50 values ranging from 1.82 to 22.5 μg/mL. Noticeably, fungicide whole-plant assays indicated that 6 showed excellent activity on the Plasmopara viticola preventative test at 6 ppm and concentration-dependent activity on the Phytophthora infestans preventative application at 200, 60, and 20 ppm. Preliminary structure-activity relationships are also discussed.
Chang-lun Shao - One of the best experts on this subject based on the ideXlab platform.
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Annular oxygenation and rearrangement products of cryptotanshinone by biotransformation with marine-derived fungi Cochliobolus lunatus and Aspergillus terreus.
Bioorganic chemistry, 2020Co-Authors: Qin-yu Meng, Chang-lun Shao, Xiao-hui Shi, Ya-hui Zhang, Peng Zhang, Chang-yun WangAbstract:Abstract Structural modification of natural products by biotransformation with fungi is an attractive tool to obtain novel bioactive derivatives. In the present study, cryptotanshinone (1), a quinoid abietane diterpene from traditional Chinese medicine Salvia miltiorrhiza (Danshen), was transformed by two marine-derived fungi. By using Cochliobolus lunatus TA26-46, one new oxygenated and rearranged product (2), containing a 5,6-dihydropyrano[4,3-b]chromene moiety, together with one known metabolite (10), were obtained from the converted broth of cryptotanshinone (1) with the isolated yields of 1.0% and 2.1%, respectively. While, under the action of Aspergillus terreus RA2905, seven new transformation products (3–9) as well as 10 with the fragments of 2-methylpropan-1-ol and oxygenated p-benzoquinone were produced and obtained with the isolated yields of 0.1%–1.3%. The structures of the new compounds were elucidated by comprehensive spectroscopic analysis including High Resolution Electrospray Ionization Mass Spectroscopy (HRESIMS), Nuclear Magnetic Resonance (NMR) and Electronic Circular Dichroism (ECD). The metabolic pathways of cryptotanshinone by these two fungi were presumed to be the opening and rearrangement of furan ring, and/or oxygenation of cyclohexane ring. Cryptotanshinone (1) and its metabolites displayed anti-inflammatory activities against NO production in LPS-stimulated BV-2 cells and antibacterial activities towards methicillin-resistant Staphylococcus aureus. These findings revealed the potential of marine fungi to transform the structures of natural products by biotransformation.
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Co-cultivation With 5-Azacytidine Induced New Metabolites From the Zoanthid-Derived Fungus Cochliobolus lunatus.
Frontiers in chemistry, 2019Co-Authors: Xiao-hui Shi, Chang-lun Shao, Ya-hui Zhang, Kai-xian Chen, Yue-wei Guo, Chang-yun WangAbstract:The zoanthid-derived fungus Cochliobolus lunatus (TA26-46) has been proven to be a source of bioactive 14-membered resorcylic acid lactones (RALs). In the present study, chemical epigenetic manipulation was applied to this fungal strain with a DNA methyltransferase inhibitor resulting in the significant changes of the secondary metabolites. Cultivation of C. lunatus (TA26-46) with 10 μM 5-azacytidine in Czapek-Dox liquid medium led to the isolation of new types of metabolites, including two α-pyrones, cochliobopyrones A (1) and B (2), along with three isocoumarins (3-5) and one chromone (6). The planar structures of the new compounds (1-2) were elucidated by comprehensive analyses of NMR and HRESIMS data. Their challenging relative configurations were established by a combination of acetonide reaction, coupling constants and NOESY correlations analysis, and DP4+ probability calculation. Their absolute configurations were determined by comparing with the ECD calculation data of the fragment molecules, 6-(1,2-dihydroxypropyl)-4-methoxy-2H-pyran-2-ones. It is the first time to obtain α-pyrone compounds with the epoxy ring or bromine atom on the seven-numbered side chain. It could be concluded that chemical epigenetic agents could induce C. lunatus to produce new types of secondary metabolites differing from its original products (RALs).
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Cochliomycin G, a 14-membered resorcylic acid lactone from a marine-derived fungus Cochliobolus lunatus.
Natural product research, 2019Co-Authors: Xiao-jia Xue, Chang-yun Wang, Chang-lun ShaoAbstract:Cochliomycin G (1), a new 14-membered resorcylic acid lactone, together with six known analogues (2−7), was isolated from the culture broth of a marine-derived fungus Cochliobolus lunatus. The plan...
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DNA Methyltransferase Inhibitor Induced Fungal Biosynthetic Products: Diethylene Glycol Phthalate Ester Oligomers from the Marine-Derived Fungus Cochliobolus lunatus
Marine biotechnology (New York N.Y.), 2016Co-Authors: Min Chen, Wei Zhang, Chang-lun Shao, Zhen-ming Chi, Chang-yun WangAbstract:Chemical epigenetic manipulation was applied to the marine-derived fungus Cochliobolus lunatus (TA26–46) with a DNA methyltransferase inhibitor resulting in the significant changes of the secondary metabolites. Cultivation of C. lunatus (TA26–46) with 5-azacytidine led to the isolation of seven new diethylene glycol phthalate esters, cochphthesters A−G (1−6, 10), along with four known analogues (7−9, 11). Their structures were determined by extensive NMR spectroscopic spectra as well as MS data. Compounds 2−6 and 8−11, characterized by the cross-polymerization of phthalate across diethylene glycol via ester bonds, represent the first example of naturally occurring phthalate ester oligomers.
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Antifouling and Fungicidal Resorcylic Acid Lactones from the Sea Anemone-Derived Fungus Cochliobolus lunatus.
Journal of agricultural and food chemistry, 2014Co-Authors: Qing-ai Liu, Min Chen, Chang-lun Shao, Mathias Blum, Li-she Gan, Kai-ling Wang, Chang-yun WangAbstract:Three new 14-membered resorcylic acid lactones, cochliomycins D-F, 1-3, and eight known analogues, 4-11, were isolated from the sea anemone-derived fungus Cochliobolus lunatus. Compounds 1-4 are diastereomers differing from each other by the absolute configurations of the 4',5'-diol chiral centers. The absolute configurations of 1-4 were established by the CD exciton chirality method and TDDFT ECD calculations. In antifouling assays, 1, 3-6, and 6a exhibited potent antifouling activities against the larval settlement of the barnacle Balanus amphitrite at nontoxic concentrations, with EC50 values ranging from 1.82 to 22.5 μg/mL. Noticeably, fungicide whole-plant assays indicated that 6 showed excellent activity on the Plasmopara viticola preventative test at 6 ppm and concentration-dependent activity on the Phytophthora infestans preventative application at 200, 60, and 20 ppm. Preliminary structure-activity relationships are also discussed.
Jerzy Adamski - One of the best experts on this subject based on the ideXlab platform.
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Dimerization and enzymatic activity of fungal 17β-hydroxysteroid dehydrogenase from the short-chain dehydrogenase/reductase superfamily
BMC biochemistry, 2005Co-Authors: Katja Kristan, Jerzy Adamski, Jure Stojan, Dominga Deluca, Tea Lanišnik RižnerAbstract:Background 17β-hydroxysteroid dehydrogenase from the fungus Cochliobolus lunatus (17β-HSDcl) is a member of the short-chain dehydrogenase/reductase (SDR) superfamily. SDR proteins usually function as dimers or tetramers and 17β-HSDcl is also a homodimer under native conditions.
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Significance of individual amino acid residues for coenzyme and substrate specificity of 17beta-hydroxysteroid dehydrogenase from the fungus Cochliobolus lunatus.
Chemico-biological interactions, 2003Co-Authors: Katja Kristan, Tea Lanišnik Rižner, Jure Stojan, Josef K. Gerber, Elisabeth Kremmer, Jerzy AdamskiAbstract:17beta-Hydroxysteroid dehydrogenase from the fungus Cochliobolus lunatus (17beta-HSDcl) is a NADPH dependent member of the short-chain dehydrogenase reductase (SDR) superfamily. Recently, we prepared a homology-built structural model of 17beta-HSDcl using the known three-dimensional structure of homologous 1,3,8-trihydroxynaphthalene reductase from the fungus Magnaporthe grisea. This model structure directed our studies of structure-function relationship of the fungal 17beta-HSD, as one of the model enzymes of the SDR superfamily. In this work, we investigated the significance of individual amino acid residues for coenzyme and substrate specificity. We performed site directed mutagenesis of R28, a basic residue conserved in most NADPH dependent SDR structures; T200, found only in Streptomyces hydrogenans 3alpha,20beta-HSD and Drosophila alcohol dehydrogenases; and H230, a residue corresponding to the substrate specificity important H221 in human 17beta-HSD type 1. All recombinant proteins were expressed in Escherichia coli and purified to homogeneity. Kinetic evaluation of individual mutations was performed by analysis of progress curves of interconversions between 4-estrene-3,17-dione and 4-estrene-17beta-ol-3-one, in the presence of NADPH and NADP(+); according to the Theorell-Chance reaction mechanism. The results demonstrate the role of the selected amino acid residues; R28 seems to interact with the NADPH 2'-phosphate group; T200 may be involved in binding and dissociation of NADPH/NADP(+); while H230 and the neighboring A231 appears not to be responsible for substrate specificity of 17beta-HSDcl.
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Significance of individual amino acid residues for coenzyme and substrate specificity of 17β-hydroxysteroid dehydrogenase from the fungus Cochliobolus lunatus
Chemico-Biological Interactions, 2003Co-Authors: Katja Kristan, Tea Lanišnik Rižner, Jure Stojan, Josef K. Gerber, Elisabeth Kremmer, Jerzy AdamskiAbstract:Abstract 17β-Hydroxysteroid dehydrogenase from the fungus Cochliobolus lunatus (17β-HSDcl) is a NADPH dependent member of the short-chain dehydrogenase reductase (SDR) superfamily. Recently, we prepared a homology-built structural model of 17β-HSDcl using the known three-dimensional structure of homologous 1,3,8-trihydroxynaphthalene reductase from the fungus Magnaporthe grisea . This model structure directed our studies of structure–function relationship of the fungal 17β-HSD, as one of the model enzymes of the SDR superfamily. In this work, we investigated the significance of individual amino acid residues for coenzyme and substrate specificity. We performed site directed mutagenesis of R28, a basic residue conserved in most NADPH dependent SDR structures; T200, found only in Streptomyces hydrogenans 3α,20β-HSD and Drosophila alcohol dehydrogenases; and H230, a residue corresponding to the substrate specificity important H221 in human 17β-HSD type 1. All recombinant proteins were expressed in Escherichia coli and purified to homogeneity. Kinetic evaluation of individual mutations was performed by analysis of progress curves of interconversions between 4-estrene-3,17-dione and 4-estrene-17β-ol-3-one, in the presence of NADPH and NADP + ; according to the Theorell–Chance reaction mechanism. The results demonstrate the role of the selected amino acid residues; R28 seems to interact with the NADPH 2′-phosphate group; T200 may be involved in binding and dissociation of NADPH/NADP + ; while H230 and the neighboring A231 appears not to be responsible for substrate specificity of 17β-HSDcl.
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Searching for the physiological function of 17β-hydroxysteroid dehydrogenase from the fungus Cochliobolus lunatus: studies of substrate specificity and expression analysis
Molecular and Cellular Endocrinology, 2001Co-Authors: Tea Lanišnik Rižner, Jure Stojan, Jerzy AdamskiAbstract:17beta-hydroxysteroid dehydrogenase from the filamentous fungus Cochliobolus lunatus (17beta-HSDcl) has recently been characterized. Since its function is still unclear, we performed substrate specificity studies to obtain some indications about its physiological function. Different steroids were studied as putative substrates of recombinant 17beta-HSDcl, androgens and estrogens, brassinosteroids, and the fungal steroid herbarulid. Among these androgens and estrogens were most efficiently converted. The following substrates in decreasing order were best reduced: 4-estrene-3,17-dione, 5alpha-androstane-3,17-dione, 4-androstene-3,17-dione and estrone. Two typical inhibitors were tested: carbenoxolone--a representative inhibitor of the SDR family and quercetin--a diagnostic inhibitor of carbonyl reductases. Among these two quercetin was more efficient. Expression studies revealed that 17beta-HSDcl is mainly expressed in the stationary phase of growth indicating its possible involvement in secondary metabolism.
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17β-Hydroxysteroid Dehydrogenase from Cochliobolus lunatus: Model Structure and Substrate Specificity
Archives of biochemistry and biophysics, 2000Co-Authors: Tea Lanišnik Rižner, Jerzy Adamski, Jure StojanAbstract:Abstract A homology-built structural model of 17β-hydroxysteroid dehydrogenase from the fungus Cochliobolus lunatus, a member of the short-chain dehydrogenase/reductase family, was worked out using the known three-dimensional structure of trihydroxynaphthalene reductase (EC 1.3.1.50) from Magnaporthe grisea as a template. Due to 61% sequence identity, the model also revealed a similar backbone trace. On the basis of qualitative thin-layer chromatography and comparative kinetic tests of the activity toward various potential steroid substrates, we conclude that androgens are more efficiently converted than estrogens. Their specific oxidoreduction predominantly occurs at the C17 position while no significant conversion at C3 and C20 was determined. Additionally, a thousand times less effective inhibition by 5-methyl-(1,2,4)-triazolo[3,4-b]benzothiazole and no activity toward 2,3-dihydro-2,5-dihydroxy-4H-benzopyran-4-one indicate distinct specificies of 17β-hydroxysteroid dehydrogenase from the fungus C. lunatus and trihydroxynaphthalene reductase. The results of the analysis of progress curve measurements for the forward and backward reactions are consistent with the Theorell–Chance reaction mechanism also predicted from the structural model. In accordance with these results, 4-androstene-3,17-dione was docked into the enzyme active site using molecular modeling and dynamics calculations.
Radovan Komel - One of the best experts on this subject based on the ideXlab platform.
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Benzoic acid derivatives with improved antifungal activity: Design, synthesis, structure–activity relationship (SAR) and CYP53 docking studies
Bioorganic & medicinal chemistry, 2015Co-Authors: Sabina Berne, Nada Kraševec, Stanislav Gobec, Matej Sova, Lidija Kovačič, Igor Križaj, Radovan KomelAbstract:Previously, we identified CYP53 as a fungal-specific target of natural phenolic antifungal compounds and discovered several inhibitors with antifungal properties. In this study, we performed similarity-based virtual screening and synthesis to obtain benzoic acid-derived compounds and assessed their antifungal activity against Cochliobolus lunatus, Aspergillus niger and Pleurotus ostreatus. In addition, we generated structural models of CYP53 enzyme and used them in docking trials with 40 selected compounds. Finally, we explored CYP53-ligand interactions and identified structural elements conferring increased antifungal activity to facilitate the development of potential new antifungal agents that specifically target CYP53 enzymes of animal and plant pathogenic fungi.
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Berne et al.: Progesterone-induced Gene Expression Profile... Scientific paper Progesterone-induced Gene Expression Profile of the Filamentous Fungus Cochliobolus lunatus
2015Co-Authors: Sabina Berne, Ljerka Lah, Radovan KomelAbstract:Suppression subtractive hybridization (SSH) was employed to study differential gene expression upon progesterone treatment of the filamentous fungus Cochliobolus lunatus, a plant and opportunistic human pathogen. The transcription profile of progesterone-induced vs. non-induced C. lunatus revealed changes in the number of genes involved in facilitated and vesicle mediated transport, amino acid and derivative metabolism, protein biosynthesis, cell wall biogenesis, lipid metabolism, carbohydrate metabolism, and generation of precursor metabolites and energy. These results suggest that progesterone induces a global adaptive stress response in the organism. Such a response is not surprising, as the steroidal ring structure is similar to certain antifungal plant defense compounds. In C. lunatus, the conversion of such molecules to hydroxylated and less-toxic substances is mediated by enzymes of the cytochrome P450 superfamily, however little is known of the genes encoding them. We identified several putative cytochrome P450 cDNA sequences and quantitatively analyzed their relative mRNA levels upon progesterone induction using Real-time RT-PCR. None of the selected cytochromes P450 showed significant up-regulation (more than 2 fold induction). As an additional inevitable consequence of the large-scale sequencing of cDNA clones, valuable insight into the genome of this non-model organism was obtained
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CYP53A15 of Cochliobolus lunatus, a target for natural antifungal compounds.
Journal of medicinal chemistry, 2008Co-Authors: Barbara Podobnik, Tea Lanišnik Rižner, Damjana Rozman, Jure Stojan, Ljerka Lah, Nada Kraševec, Matej Seliškar, Radovan KomelAbstract:A novel cytochrome P450, CYP53A15, was identified in the pathogenic filamentous ascomycete Cochliobolus lunatus. The protein, classified into the CYP53 family, was capable of para hydroxylation of benzoate. Benzoate is a key intermediate in the metabolism of aromatic compounds in fungi and yet basically toxic to the organism. To guide functional analyses, protein structure was predicted by homology modeling. Since many naturally occurring antifungal phenolic compounds are structurally similar to CYP53A15 substrates, we tested their putative binding into the active site of CYP53A15. Some of these compounds inhibited CYP53A15. Increased antifungal activity was observed when tested in the presence of benzoate. Some results suggest that CYP53A15 O-demethylation activity is important in detoxification of other antifungal substances. With the design of potent inhibitors, CYP53 enzymes could serve as alternative antifungal drug targets.
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Progesterone-induced Gene Expression Profile of the Filamentous Fungus Cochliobolus lunatus
Acta Chimica Slovenica, 2008Co-Authors: Sabina Berne, Nada Kraševec, Ljerka Lah, Branka Korošec, Radovan KomelAbstract:Suppression subtractive hybridization (SSH) was employed to study differential gene expression upon progesterone treatment of the filamentous fungus Cochliobolus lunatus, a plant and opportunistic human pathogen. The transcription profile of progesterone-induced vs. non-induced C. lunatus revealed changes in the number of genes involved in facilitated and vesicle mediated transport, amino acid and derivative metabolism, protein biosynthesis, cell wall biogenesis, lipid metabolism, carbohydrate metabolism, and generation of precursor metabolites and energy. These results suggest that progesterone induces a global adaptive stress response in the organism. Such a response is not surprising, as the steroidal ring structure is similar to certain antifungal plant defense compounds. In C. lunatus, the conversion of such molecules to hydroxylated and less-toxic substances is mediated by enzymes of the cytochrome P450 superfamily, however little is known of the genes encoding them. We identified several putative cytochrome P450 cDNA sequences and quantitatively analyzed their relative mRNA levels upon progesterone induction using Real-time RT-PCR. None of the selected cytochromes P450 showed significant up-regulation (more than 2 fold induction). As an additional inevitable consequence of the large-scale sequencing of cDNA clones, valuable insight into the genome of this non-model organism was obtained.
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11β-Hydroxysteroid dehydrogenase activity in progesterone biotransformation by the filamentous fungus Cochliobolus lunatus
The Journal of Steroid Biochemistry and Molecular Biology, 1997Co-Authors: M Vitas, T Pajic, Steven L. Kelly, Radovan KomelAbstract:Abstract Progesterone biotransformation was examined in relation to hydroxylating and dehydrogenating enzymes of Cochliobolus lunatus . 11β-hydroxysteroid dehydrogenase activity (11β-HSD) was located in cytosolic fraction and was NADP-dependent, inducible by progesterone and apparently unidirectional. Several inhibitors of 11β-hydroxysteroid dehydrogenase were tested; furosemide, glycyrrhizic-acid and carbenoxolone did not influence the dehydrogenation of 11β-hydroxy-4-pregnene-3,20-dione to 4-pregnene-3,11,20-trione, although grapefruit juice significantly reduced the rate of progesterone hydroxylation.