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Váradi G, Batta G, Galgóczy L, Hajdu D, Fizil Á, Czajlik A, Virágh M, Kele Z, Meyer V, Jung S, Marx F, Tóth GK. Confirmation of the Disulfide Connectivity and Strategies for Chemical Synthesis of the Four-Disulfide-Bond-Stabilized Aspergillus giganteus Antifungal Protein, AFP. JOURNAL OF NATURAL PRODUCTS 2023; 86:782-790. [PMID: 36847642 PMCID: PMC10152477 DOI: 10.1021/acs.jnatprod.2c00954] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Emerging fungal infections require new, more efficient antifungal agents and therapies. AFP, a protein from Aspergillus giganteus with four disulfide bonds, is a promising candidate because it selectively inhibits the growth of filamentous fungi. In this work, the reduced form of AFP was prepared using native chemical ligation. The native protein was synthesized via oxidative folding with uniform protection for cysteine thiols. AFP's biological activity depends heavily on the pattern of natural disulfide bonds. Enzymatic digestion and MS analysis provide proof for interlocking disulfide topology (abcdabcd) that was previously assumed. With this knowledge, a semi-orthogonal thiol protection method was designed. By following this strategy, out of a possible 105, only 6 disulfide isomers formed and 1 of them proved to be identical with the native protein. This approach allows the synthesis of analogs for examining structure-activity relationships and, thus, preparing AFP variants with higher antifungal activity.
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Affiliation(s)
- Györgyi Váradi
- Department of Medical Chemistry, University of Szeged, Szeged 6720, Hungary
| | - Gyula Batta
- Department of Organic Chemistry, University of Debrecen, Debrecen 4010, Hungary
| | - László Galgóczy
- Institute of Molecular Biology, Biocenter, Medical University of Innsbruck, Innsbruck 6020, Austria
- Institute of Biochemistry, Biological Research Centre, Eötvös Loránd Research Network, Szeged 6726, Hungary
| | - Dorottya Hajdu
- Department of Organic Chemistry, University of Debrecen, Debrecen 4010, Hungary
| | - Ádám Fizil
- Department of Organic Chemistry, University of Debrecen, Debrecen 4010, Hungary
| | - András Czajlik
- Department of Organic Chemistry, University of Debrecen, Debrecen 4010, Hungary
| | - Máté Virágh
- Department of Microbiology, Faculty of Science and Informatics, University of Szeged, Szeged 6726, Hungary
| | - Zoltán Kele
- Department of Medical Chemistry, University of Szeged, Szeged 6720, Hungary
| | - Vera Meyer
- Department of Applied and Molecular Microbiology Technische Universität Berlin, Institute of Biotechnology, Berlin 13355, Germany
| | - Sascha Jung
- Department of Applied and Molecular Microbiology Technische Universität Berlin, Institute of Biotechnology, Berlin 13355, Germany
| | - Florentine Marx
- Institute of Molecular Biology, Biocenter, Medical University of Innsbruck, Innsbruck 6020, Austria
| | - Gábor K Tóth
- Department of Medical Chemistry, University of Szeged, Szeged 6720, Hungary
- MTA-SZTE Biomimetic Systems Research Group, University of Szeged, Szeged 6720, Hungary
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2
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Giner-Llorca M, Gallego del Sol F, Marcos JF, Marina A, Manzanares P. Rationally designed antifungal protein chimeras reveal new insights into structure-activity relationship. Int J Biol Macromol 2023; 225:135-148. [PMID: 36460243 DOI: 10.1016/j.ijbiomac.2022.11.280] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 11/25/2022] [Accepted: 11/27/2022] [Indexed: 11/30/2022]
Abstract
Antifungal proteins (AFPs) are promising antimicrobial compounds that represent a feasible alternative to fungicides. Penicillium expansum encodes three phylogenetically distinct AFPs (PeAfpA, PeAfpB and PeAfpC) which show different antifungal profiles and fruit protection effects. To gain knowledge about the structural determinants governing their activity, we solved the crystal structure of PeAfpB and rationally designed five PeAfpA::PeAfpB chimeras (chPeAFPV1-V5). Chimeras showed significant differences in their antifungal activity. chPeAFPV1 and chPeAFPV2 improved the parental PeAfpB potency, and it was very similar to that of PeAfpA. chPeAFPV4 and chPeAFPV5 showed an intermediate profile of activity compared to the parental proteins while chPeAFPV3 was inactive towards most of the fungi tested. Structural analysis of the chimeras evidenced an identical scaffold to PeAfpB, suggesting that the differences in activity are due to the contributions of specific residues and not to induced conformational changes or structural rearrangements. Results suggest that mannoproteins determine protein interaction with the cell wall and its antifungal activity while there is not a direct correlation between binding to membrane phospholipids and activity. This work provides new insights about the relevance of sequence motifs and the feasibility of modifying protein specificity, opening the door to the rational design of chimeras with biotechnological applicability.
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Affiliation(s)
- Moisés Giner-Llorca
- Food Biotechnology Department, Instituto de Agroquímica y Tecnología de Alimentos (IATA), Consejo Superior de Investigaciones Científicas (CSIC), Catedrático Agustín Escardino Benlloch 7, 46980 Paterna, Valencia, Spain
| | - Francisca Gallego del Sol
- Instituto de Biomedicina de Valencia (IBV), CSIC and CIBER de Enfermedades Raras (CIBERER), Jaume Roig 11, 46010, Valencia, Spain
| | - Jose F Marcos
- Food Biotechnology Department, Instituto de Agroquímica y Tecnología de Alimentos (IATA), Consejo Superior de Investigaciones Científicas (CSIC), Catedrático Agustín Escardino Benlloch 7, 46980 Paterna, Valencia, Spain
| | - Alberto Marina
- Instituto de Biomedicina de Valencia (IBV), CSIC and CIBER de Enfermedades Raras (CIBERER), Jaume Roig 11, 46010, Valencia, Spain.
| | - Paloma Manzanares
- Food Biotechnology Department, Instituto de Agroquímica y Tecnología de Alimentos (IATA), Consejo Superior de Investigaciones Científicas (CSIC), Catedrático Agustín Escardino Benlloch 7, 46980 Paterna, Valencia, Spain.
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DMSO-Induced Unfolding of the Antifungal Disulfide Protein PAF and Its Inactive Variant: A Combined NMR and DSC Study. Int J Mol Sci 2023; 24:ijms24021208. [PMID: 36674720 PMCID: PMC9864379 DOI: 10.3390/ijms24021208] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 01/03/2023] [Accepted: 01/05/2023] [Indexed: 01/11/2023] Open
Abstract
PAF and related antifungal proteins are promising antimicrobial agents. They have highly stable folds around room temperature due to the presence of 3-4 disulfide bonds. However, unfolded states persist and contribute to the thermal equilibrium in aqueous solution, and low-populated states might influence their biological impact. To explore such equilibria during dimethyl sulfoxide (DMSO)-induced chemical unfolding, we studied PAF and its inactive variant PAFD19S using nuclear magnetic resonance (NMR) and differential scanning calorimetry (DSC). According to the NMR monitoring at 310 K, the folded structures disappear above 80 v/v% DMSO concentration, while the unfolding is completely reversible. Evaluation of a few resolved peaks from viscosity-compensated 15N-1H HSQC spectra of PAF yielded ∆G = 23 ± 7 kJ/M as the average value for NMR unfolding enthalpy. The NMR-based structures of PAF and the mutant in 50 v/v% DMSO/H2O mixtures were more similar in the mixed solvents then they were in water. The 15N NMR relaxation dynamics in the same mixtures verified the rigid backbones of the NMR-visible fractions of the proteins; still, enhanced dynamics around the termini and some loops were observed. DSC monitoring of the Tm melting point showed parabolic dependence on the DMSO molar fraction and suggested that PAF is more stable than the inactive PAFD19S. The DSC experiments were irreversible due to the applied broad temperature range, but still suggestive of the endothermic unfolding of PAF.
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Fardella PA, Tian Z, Clarke BB, Belanger FC. The Epichloë festucae Antifungal Protein Efe-AfpA Protects Creeping Bentgrass ( Agrostis stolonifera) from the Plant Pathogen Clarireedia jacksonii, the Causal Agent of Dollar Spot Disease. J Fungi (Basel) 2022; 8:jof8101097. [PMID: 36294663 PMCID: PMC9605492 DOI: 10.3390/jof8101097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 10/11/2022] [Accepted: 10/15/2022] [Indexed: 11/16/2022] Open
Abstract
Dollar spot disease, caused by the fungal pathogen Clarireedia jacksonii, is a major problem in many turfgrass species, particularly creeping bentgrass (Agrostis stolonifera). It is well-established that strong creeping red fescue (Festuca rubra subsp. rubra) exhibits good dollar spot resistance when infected by the fungal endophyte Epichloë festucae. This endophyte-mediated disease resistance is unique to the fine fescues and has not been observed in other grass species infected with other Epichloë spp. The mechanism underlying the unique endophyte-mediated disease resistance in strong creeping red fescue has not yet been established. We pursued the possibility that it may be due to the presence of an abundant secreted antifungal protein produced by E. festucae. Here, we compare the activity of the antifungal protein expressed in Escherichia coli, Pichia pastoris, and Penicillium chrysogenum. Active protein was recovered from all systems, with the best activity being from Pe. chrysogenum. In greenhouse assays, topical application of the purified antifungal protein to creeping bentgrass and endophyte-free strong creeping red fescue protected the plants from developing severe symptoms caused by C. jacksonii. These results support the hypothesis that Efe-AfpA is a major contributor to the dollar spot resistance observed with E. festucae-infected strong creeping red fescue in the field, and that this protein could be developed as an alternative or complement to fungicides for the management of this disease on turfgrasses.
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Tóth L, Poór P, Ördög A, Váradi G, Farkas A, Papp C, Bende G, Tóth GK, Rákhely G, Marx F, Galgóczy L. The combination of Neosartorya ( Aspergillus) fischeri antifungal proteins with rationally designed γ-core peptide derivatives is effective for plant and crop protection. BIOCONTROL (DORDRECHT, NETHERLANDS) 2022; 67:249-262. [PMID: 35463117 PMCID: PMC8993730 DOI: 10.1007/s10526-022-10132-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Accepted: 01/18/2022] [Indexed: 05/09/2023]
Abstract
UNLABELLED Plant pathogenic fungi are responsible for enormous crop losses worldwide. Overcoming this problem is challenging as these fungi can be highly resistant to approved chemical fungicides. There is thus a need to develop and introduce fundamentally new plant and crop protection strategies for sustainable agricultural production. Highly stable extracellular antifungal proteins (AFPs) and their rationally designed peptide derivatives (PDs) constitute feasible options to meet this challenge. In the present study, their potential for topical application to protect plants and crops as combinatorial biofungicides is supported by the investigation of two Neosartorya (Aspergillus) fischeri AFPs (NFAP and NFAP2) and their γ-core PDs. Previously, the biofungicidal potential of NFAP, its rationally designed γ-core PD (γNFAP-opt), and NFAP2 was reported. Susceptibility tests in the present study extended the in vitro antifungal spectrum of NFAP2 and its γ-core PD (γNFAP2-opt) to Botrytis, Cladosporium, and Fusarium spp. Besides, in vitro additive or indifferent interactions, and synergism were observed when NFAP or NFAP2 was applied in combination with γNFAP-opt. Except for γNFAP2-opt, the investigated proteins and peptides did not show any toxicity to tomato plant leaves. The application of NFAP in combination with γNFAP-opt effectively inhibited conidial germination, biofilm formation, and hyphal extension of the necrotrophic mold Botrytis cinerea on tomato plant leaves. However, the same combination only partially impeded the B. cinerea-mediated decay of tomato fruits, but mitigated the symptoms. Our results highlight the feasibility of using the combination of AFP and PD as biofungicide for the fungal infection control in plants and crops. SUPPLEMENTARY INFORMATION The online version contains supplementary material available at 10.1007/s10526-022-10132-y.
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Affiliation(s)
- Liliána Tóth
- Institute of Plant Biology, Biological Research Centre, Eötvös Loránd Research Network, Temesvári krt. 62, 6726 Szeged, Hungary
- Department of Biotechnology, Faculty of Science and Informatics, University of Szeged, Közép fasor 52, 6726 Szeged, Hungary
| | - Péter Poór
- Department of Plant Biology, Faculty of Science and Informatics, University of Szeged, Közép fasor 52, 6726 Szeged, Hungary
| | - Attila Ördög
- Department of Plant Biology, Faculty of Science and Informatics, University of Szeged, Közép fasor 52, 6726 Szeged, Hungary
| | - Györgyi Váradi
- Department of Medical Chemistry, Faculty of Medicine, University of Szeged, Dóm tér 8, 6720 Szeged, Hungary
| | - Attila Farkas
- Institute of Plant Biology, Biological Research Centre, Eötvös Loránd Research Network, Temesvári krt. 62, 6726 Szeged, Hungary
| | - Csaba Papp
- Department of Microbiology, Faculty of Science and Informatics, University of Szeged, Közép fasor 52, 6726 Szeged, Hungary
| | - Gábor Bende
- Department of Biotechnology, Faculty of Science and Informatics, University of Szeged, Közép fasor 52, 6726 Szeged, Hungary
| | - Gábor K. Tóth
- Department of Medical Chemistry, Faculty of Medicine, University of Szeged, Dóm tér 8, 6720 Szeged, Hungary
- MTA-SZTE Biomimetic Systems Research Group, University of Szeged, Dóm tér 8, 6720 Szeged, Hungary
| | - Gábor Rákhely
- Department of Biotechnology, Faculty of Science and Informatics, University of Szeged, Közép fasor 52, 6726 Szeged, Hungary
- Institute of Biophysics, Biological Research Centre, Eötvös Loránd Research Network, Temesvári krt. 62, 6726 Szeged, Hungary
| | - Florentine Marx
- Institute of Molecular Biology, Biocenter, Medical University of Innsbruck, Innrain 80-82, 6020 Innsbruck, Austria
| | - László Galgóczy
- Institute of Plant Biology, Biological Research Centre, Eötvös Loránd Research Network, Temesvári krt. 62, 6726 Szeged, Hungary
- Department of Biotechnology, Faculty of Science and Informatics, University of Szeged, Közép fasor 52, 6726 Szeged, Hungary
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Struyfs C, Cammue BPA, Thevissen K. Membrane-Interacting Antifungal Peptides. Front Cell Dev Biol 2021; 9:649875. [PMID: 33912564 PMCID: PMC8074791 DOI: 10.3389/fcell.2021.649875] [Citation(s) in RCA: 51] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Accepted: 03/09/2021] [Indexed: 12/17/2022] Open
Abstract
The incidence of invasive fungal infections is increasing worldwide, resulting in more than 1.6 million deaths every year. Due to growing antifungal drug resistance and the limited number of currently used antimycotics, there is a clear need for novel antifungal strategies. In this context, great potential is attributed to antimicrobial peptides (AMPs) that are part of the innate immune system of organisms. These peptides are known for their broad-spectrum activity that can be directed toward bacteria, fungi, viruses, and/or even cancer cells. Some AMPs act via rapid physical disruption of microbial cell membranes at high concentrations causing cell leakage and cell death. However, more complex mechanisms are also observed, such as interaction with specific lipids, production of reactive oxygen species, programmed cell death, and autophagy. This review summarizes the structure and mode of action of antifungal AMPs, thereby focusing on their interaction with fungal membranes.
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Affiliation(s)
- Caroline Struyfs
- Centre of Microbial and Plant Genetics, KU Leuven, Leuven, Belgium
| | - Bruno P A Cammue
- Centre of Microbial and Plant Genetics, KU Leuven, Leuven, Belgium
| | - Karin Thevissen
- Centre of Microbial and Plant Genetics, KU Leuven, Leuven, Belgium
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Zhao Z, Cai F, Gao R, Ding M, Jiang S, Chen P, Pang G, Chenthamara K, Shen Q, Bayram Akcapinar G, Druzhinina IS. At least three families of hyphosphere small secreted cysteine-rich proteins can optimize surface properties to a moderately hydrophilic state suitable for fungal attachment. Environ Microbiol 2021; 23:5750-5768. [PMID: 33538393 PMCID: PMC8596622 DOI: 10.1111/1462-2920.15413] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 01/25/2021] [Accepted: 01/26/2021] [Indexed: 12/11/2022]
Abstract
The secretomes of filamentous fungi contain a diversity of small secreted cysteine‐rich proteins (SSCPs) that have a variety of properties ranging from toxicity to surface activity. Some SSCPs are recognized by other organisms as indicators of fungal presence, but their function in fungi is not fully understood. We detected a new family of fungal surface‐active SSCPs (saSSCPs), here named hyphosphere proteins (HFSs). An evolutionary analysis of the HFSs in Pezizomycotina revealed a unique pattern of eight single cysteine residues (C‐CXXXC‐C‐C‐C‐C‐C) and a long evolutionary history of multiple gene duplications and ancient interfungal lateral gene transfers, suggesting their functional significance for fungi with different lifestyles. Interestingly, recombinantly produced saSSCPs from three families (HFSs, hydrophobins and cerato‐platanins) showed convergent surface‐modulating activity on glass and on poly(ethylene‐terephthalate), transforming their surfaces to a moderately hydrophilic state, which significantly favoured subsequent hyphal attachment. The addition of purified saSSCPs to the tomato rhizosphere had mixed effects on hyphal attachment to roots, while all tested saSSCPs had an adverse effect on plant growth in vitro. We propose that the exceptionally high diversity of saSSCPs in Trichoderma and other fungi evolved to efficiently condition various surfaces in the hyphosphere to a fungal‐beneficial state.
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Affiliation(s)
- Zheng Zhao
- Key Laboratory of Plant Immunity, Jiangsu Provincial Key Lab of Solid Organic Waste Utilization, Nanjing Agricultural University, Nanjing, China.,Fungal Genomics Laboratory (FungiG), Nanjing Agricultural University, Nanjing, China
| | - Feng Cai
- Key Laboratory of Plant Immunity, Jiangsu Provincial Key Lab of Solid Organic Waste Utilization, Nanjing Agricultural University, Nanjing, China.,Fungal Genomics Laboratory (FungiG), Nanjing Agricultural University, Nanjing, China.,Institute of Chemical, Environmental and Bioscience Engineering (ICEBE), TU Wien, Vienna, Austria
| | - Renwei Gao
- Key Laboratory of Plant Immunity, Jiangsu Provincial Key Lab of Solid Organic Waste Utilization, Nanjing Agricultural University, Nanjing, China.,Fungal Genomics Laboratory (FungiG), Nanjing Agricultural University, Nanjing, China
| | - Mingyue Ding
- Key Laboratory of Plant Immunity, Jiangsu Provincial Key Lab of Solid Organic Waste Utilization, Nanjing Agricultural University, Nanjing, China.,Fungal Genomics Laboratory (FungiG), Nanjing Agricultural University, Nanjing, China
| | - Siqi Jiang
- Key Laboratory of Plant Immunity, Jiangsu Provincial Key Lab of Solid Organic Waste Utilization, Nanjing Agricultural University, Nanjing, China.,Fungal Genomics Laboratory (FungiG), Nanjing Agricultural University, Nanjing, China
| | - Peijie Chen
- Key Laboratory of Plant Immunity, Jiangsu Provincial Key Lab of Solid Organic Waste Utilization, Nanjing Agricultural University, Nanjing, China.,Fungal Genomics Laboratory (FungiG), Nanjing Agricultural University, Nanjing, China
| | - Guan Pang
- Key Laboratory of Plant Immunity, Jiangsu Provincial Key Lab of Solid Organic Waste Utilization, Nanjing Agricultural University, Nanjing, China.,Fungal Genomics Laboratory (FungiG), Nanjing Agricultural University, Nanjing, China
| | - Komal Chenthamara
- Institute of Chemical, Environmental and Bioscience Engineering (ICEBE), TU Wien, Vienna, Austria
| | - Qirong Shen
- Key Laboratory of Plant Immunity, Jiangsu Provincial Key Lab of Solid Organic Waste Utilization, Nanjing Agricultural University, Nanjing, China
| | - Günseli Bayram Akcapinar
- Department of Medical Biotechnology, Institute of Health Sciences, Acibadem Mehmet Ali Aydinlar University, Istanbul, Turkey
| | - Irina S Druzhinina
- Key Laboratory of Plant Immunity, Jiangsu Provincial Key Lab of Solid Organic Waste Utilization, Nanjing Agricultural University, Nanjing, China.,Fungal Genomics Laboratory (FungiG), Nanjing Agricultural University, Nanjing, China.,Institute of Chemical, Environmental and Bioscience Engineering (ICEBE), TU Wien, Vienna, Austria
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8
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Czajlik A, Holzknecht J, Galgóczy L, Tóth L, Poór P, Ördög A, Váradi G, Kühbacher A, Borics A, Tóth GK, Marx F, Batta G. Solution Structure, Dynamics, and New Antifungal Aspects of the Cysteine-Rich Miniprotein PAFC. Int J Mol Sci 2021; 22:1183. [PMID: 33504082 PMCID: PMC7865535 DOI: 10.3390/ijms22031183] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 01/18/2021] [Accepted: 01/20/2021] [Indexed: 12/29/2022] Open
Abstract
The genome of Penicillium chrysogenum Q176 contains a gene coding for the 88-amino-acid (aa)-long glycine- and cysteine-rich P. chrysogenum antifungal protein C (PAFC). After maturation, the secreted antifungal miniprotein (MP) comprises 64 aa and shares 80% aa identity with the bubble protein (BP) from Penicillium brevicompactum, which has a published X-ray structure. Our team expressed isotope (15N, 13C)-labeled, recombinant PAFC in high yields, which allowed us to determine the solution structure and molecular dynamics by nuclear magnetic resonance (NMR) experiments. The primary structure of PAFC is dominated by 14 glycines, and therefore, whether the four disulfide bonds can stabilize the fold is challenging. Indeed, unlike the few published solution structures of other antifungal MPs from filamentous ascomycetes, the NMR data indicate that PAFC has shorter secondary structure elements and lacks the typical β-barrel structure, though it has a positively charged cavity and a hydrophobic core around the disulfide bonds. Some parts within the two putative γ-core motifs exhibited enhanced dynamics according to a new disorder index presentation of 15N-NMR relaxation data. Furthermore, we also provided a more detailed insight into the antifungal spectrum of PAFC, with specific emphasis on fungal plant pathogens. Our results suggest that PAFC could be an effective candidate for the development of new antifungal strategies in agriculture.
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Affiliation(s)
- András Czajlik
- Department of Organic Chemistry, Faculty of Science and Technology, University of Debrecen, H-4032 Debrecen, Hungary;
| | - Jeanett Holzknecht
- Institute of Molecular Biology, Biocenter, Medical University of Innsbruck, A-6020 Innsbruck, Austria; (J.H.); (A.K.)
| | - László Galgóczy
- Institute of Plant Biology, Biological Research Centre, Eötvös Loránd Research Network, H-6726 Szeged, Hungary; (L.G.); (L.T.)
- Department of Biotechnology, Faculty of Science and Informatics, University of Szeged, H-6726 Szeged, Hungary
| | - Liliána Tóth
- Institute of Plant Biology, Biological Research Centre, Eötvös Loránd Research Network, H-6726 Szeged, Hungary; (L.G.); (L.T.)
- Department of Biotechnology, Faculty of Science and Informatics, University of Szeged, H-6726 Szeged, Hungary
| | - Péter Poór
- Department of Plant Biology, Faculty of Sciences and Informatics, University of Szeged, H-6726 Szeged, Hungary; (P.P.); (A.Ö.)
| | - Attila Ördög
- Department of Plant Biology, Faculty of Sciences and Informatics, University of Szeged, H-6726 Szeged, Hungary; (P.P.); (A.Ö.)
| | - Györgyi Váradi
- Department of Medical Chemistry, Faculty of Medicine, University of Szeged, H-6720 Szeged, Hungary; (G.V.); (G.K.T.)
| | - Alexander Kühbacher
- Institute of Molecular Biology, Biocenter, Medical University of Innsbruck, A-6020 Innsbruck, Austria; (J.H.); (A.K.)
| | - Attila Borics
- Institute of Biochemistry, Biological Research Centre, Eötvös Loránd Research Network, H-6726 Szeged, Hungary;
| | - Gábor K. Tóth
- Department of Medical Chemistry, Faculty of Medicine, University of Szeged, H-6720 Szeged, Hungary; (G.V.); (G.K.T.)
- MTA-SZTE Biomimetic Systems Research Group, University of Szeged, Dóm tér 8, H-6720 Szeged, Hungary
| | - Florentine Marx
- Institute of Molecular Biology, Biocenter, Medical University of Innsbruck, A-6020 Innsbruck, Austria; (J.H.); (A.K.)
| | - Gyula Batta
- Department of Organic Chemistry, Faculty of Science and Technology, University of Debrecen, H-4032 Debrecen, Hungary;
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9
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Alexander AJT, Muñoz A, Marcos JF, Read ND. Calcium homeostasis plays important roles in the internalization and activities of the small synthetic antifungal peptide PAF26. Mol Microbiol 2020; 114:521-535. [PMID: 32898933 DOI: 10.1111/mmi.14532] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 05/01/2020] [Accepted: 05/17/2020] [Indexed: 01/22/2023]
Abstract
Fungal diseases are responsible for the deaths of over 1.5 million people worldwide annually. Antifungal peptides represent a useful source of antifungals with novel mechanisms-of-action, and potentially provide new methods of overcoming resistance. Here we investigate the mode-of-action of the small, rationally designed synthetic antifungal peptide PAF26 using the model fungus Neurospora crassa. Here we show that the cell killing activity of PAF26 is dependent on extracellular Ca2+ and the presence of fully functioning fungal Ca2+ homeostatic/signaling machinery. In a screen of mutants with deletions in Ca2+ -signaling machinery, we identified three mutants more tolerant to PAF26. The Ca2+ ATPase NCA-2 was found to be involved in the initial interaction of PAF26 with the cell envelope. The vacuolar Ca2+ channel YVC-1 was shown to be essential for its accumulation and concentration within the vacuolar system. The Ca2+ channel CCH-1 was found to be required to prevent the translocation of PAF26 across the plasma membrane. In the wild type, Ca2+ removal from the medium resulted in the peptide remaining trapped in small vesicles as in the Δyvc-1 mutant. It is, therefore, apparent that cell killing by PAF26 is complex and unusually dependent on extracellular Ca2+ and components of the Ca2+ -regulatory machinery.
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Affiliation(s)
- Akira J T Alexander
- Institute of Infection, Immunity & Inflammation, The University of Glasgow, Glasgow, Scotland
| | - Alberto Muñoz
- MRC Centre for Medical Mycology, University of Exeter, Exeter, UK
| | - Jose F Marcos
- Department of Food Biotechnology, Instituto de Agroquímica y Tecnología de Alimentos (IATA) , Consejo Superior de Investigaciones Científicas (CSIC), Valencia, Spain
| | - Nick D Read
- Manchester Fungal Infection Group, Infection, Immunity & Respiratory Medicine, University of Manchester, Manchester, UK
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10
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Holzknecht J, Kühbacher A, Papp C, Farkas A, Váradi G, Marcos JF, Manzanares P, Tóth GK, Galgóczy L, Marx F. The Penicillium chrysogenum Q176 Antimicrobial Protein PAFC Effectively Inhibits the Growth of the Opportunistic Human Pathogen Candida albicans. J Fungi (Basel) 2020; 6:jof6030141. [PMID: 32824977 PMCID: PMC7557831 DOI: 10.3390/jof6030141] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 08/06/2020] [Accepted: 08/11/2020] [Indexed: 12/13/2022] Open
Abstract
Small, cysteine-rich and cationic antimicrobial proteins (AMPs) from filamentous ascomycetes promise treatment alternatives to licensed antifungal drugs. In this study, we characterized the Penicillium chrysogenum Q176 antifungal protein C (PAFC), which is phylogenetically distinct to the other two Penicillium antifungal proteins, PAF and PAFB, that are expressed by this biotechnologically important ascomycete. PAFC is secreted into the culture broth and is co-expressed with PAF and PAFB in the exudates of surface cultures. This observation is in line with the suggested role of AMPs in the adaptive response of the host to endogenous and/or environmental stimuli. The in silico structural model predicted five β-strands stabilized by four intramolecular disulfide bonds in PAFC. The functional characterization of recombinant PAFC provided evidence for a promising new molecule in anti-Candida therapy. The thermotolerant PAFC killed planktonic cells and reduced the metabolic activity of sessile cells in pre-established biofilms of two Candidaalbicans strains, one of which was a fluconazole-resistant clinical isolate showing higher PAFC sensitivity than the fluconazole-sensitive strain. Candidacidal activity was linked to severe cell morphology changes, PAFC internalization, induction of intracellular reactive oxygen species and plasma membrane disintegration. The lack of hemolytic activity further corroborates the potential applicability of PAFC in clinical therapy.
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Affiliation(s)
- Jeanett Holzknecht
- Biocenter, Institute of Molecular Biology, Medical University of Innsbruck, Innrain 80–82, A-6020 Innsbruck, Austria; (J.H.); (A.K.)
| | - Alexander Kühbacher
- Biocenter, Institute of Molecular Biology, Medical University of Innsbruck, Innrain 80–82, A-6020 Innsbruck, Austria; (J.H.); (A.K.)
| | - Csaba Papp
- Department of Microbiology, Faculty of Science and Informatics, University of Szeged, Közép fasor 52, H-6726 Szeged, Hungary;
| | - Attila Farkas
- Institute of Plant Biology, Biological Research Centre, Temesvári krt. 62, H-6726 Szeged, Hungary;
| | - Györgyi Váradi
- Department of Medical Chemistry, Faculty of Medicine, University of Szeged, Dóm tér 8, H-6720 Szeged, Hungary; (G.V.); (G.K.T.)
| | - Jose F. Marcos
- Department of Food Biotechnology, Instituto de Agroquímica y Tecnología de Alimentos (IATA-CSIC), Consejo Superior de Investigaciones Científicas (CSIC), Paterna, E-46980 Valencia, Spain; (J.F.M.); (P.M.)
| | - Paloma Manzanares
- Department of Food Biotechnology, Instituto de Agroquímica y Tecnología de Alimentos (IATA-CSIC), Consejo Superior de Investigaciones Científicas (CSIC), Paterna, E-46980 Valencia, Spain; (J.F.M.); (P.M.)
| | - Gábor K. Tóth
- Department of Medical Chemistry, Faculty of Medicine, University of Szeged, Dóm tér 8, H-6720 Szeged, Hungary; (G.V.); (G.K.T.)
- MTA-SZTE Biomimetic Systems Research Group, University of Szeged, Dóm tér 8, H-6726 Szeged, Hungary
| | - László Galgóczy
- Institute of Plant Biology, Biological Research Centre, Temesvári krt. 62, H-6726 Szeged, Hungary;
- Department of Biotechnology, Faculty of Science and Informatics, University of Szeged, Közép fasor 52, H-6726 Szeged, Hungary
- Correspondence: (L.G.); (F.M.); Tel.: +36-62-599-600 (ext. 415) (L.G.); +43-512-9003 (ext. 70207) (F.M.)
| | - Florentine Marx
- Biocenter, Institute of Molecular Biology, Medical University of Innsbruck, Innrain 80–82, A-6020 Innsbruck, Austria; (J.H.); (A.K.)
- Correspondence: (L.G.); (F.M.); Tel.: +36-62-599-600 (ext. 415) (L.G.); +43-512-9003 (ext. 70207) (F.M.)
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Tóth L, Váradi G, Boros É, Borics A, Ficze H, Nagy I, Tóth GK, Rákhely G, Marx F, Galgóczy L. Biofungicidal Potential of Neosartorya ( Aspergillus) Fischeri Antifungal Protein NFAP and Novel Synthetic γ-Core Peptides. Front Microbiol 2020; 11:820. [PMID: 32477291 PMCID: PMC7237641 DOI: 10.3389/fmicb.2020.00820] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Accepted: 04/06/2020] [Indexed: 12/12/2022] Open
Abstract
Because of enormous crop losses worldwide due to pesticide-resistant plant pathogenic fungi, there is an increasing demand for the development of novel antifungal strategies in agriculture. Antifungal proteins (APs) and peptides are considered potential biofungicides; however, several factors limit their direct agricultural application, such as the high cost of production, narrow antifungal spectrum, and detrimental effects to plant development and human/animal health. This study evaluated the safety of the application of APs and peptides from the ascomycete Neosartorya fischeri as crop preservatives. The full-length N. fischeri AP (NFAP) and novel rationally designed γ-core peptide derivatives (PDs) γNFAP-opt and γNFAP-optGZ exhibited efficacy by inhibiting the growth of the agriculturally relevant filamentous ascomycetes in vitro. A high positive net charge, however, neither the hydrophilicity nor the primary structure supported the antifungal efficacy of these PDs. Further testing demonstrated that the antifungal activity did not require a conformational change of the β-pleated NFAP or the canonically ordered conformation of the synthetic PDs. Neither hemolysis nor cytotoxicity was observed when the NFAP and γNFAP-opt were applied at antifungally effective concentrations in human cell lines. Similarly, the Medicago truncatula plants that served as toxicity model and were grown from seedlings that were treated with NFAP, γNFAP-opt, or γNFAP-optGZ failed to exhibit morphological aberrations, reduction in primary root length, or the number of lateral roots. Crop protection experiments demonstrated that NFAP and associated antifungal active γ-core PDs were able to protect tomato fruits against the postharvest fungal pathogen Cladosporium herbarum.
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Affiliation(s)
- Liliána Tóth
- Institute of Plant Biology, Biological Research Centre, Szeged, Hungary
| | - Györgyi Váradi
- Department of Medical Chemistry, Faculty of Medicine, University of Szeged, Szeged, Hungary
| | - Éva Boros
- Institute of Biochemistry, Biological Research Centre, Szeged, Hungary
| | - Attila Borics
- Institute of Biochemistry, Biological Research Centre, Szeged, Hungary
| | - Hargita Ficze
- Department of Biotechnology, Faculty of Science and Informatics, University of Szeged, Szeged, Hungary
| | - István Nagy
- Institute of Biochemistry, Biological Research Centre, Szeged, Hungary
| | - Gábor K. Tóth
- Department of Medical Chemistry, Faculty of Medicine, University of Szeged, Szeged, Hungary
- MTA-SZTE Biomimetic Systems Research Group, University of Szeged, Szeged, Hungary
| | - Gábor Rákhely
- Department of Biotechnology, Faculty of Science and Informatics, University of Szeged, Szeged, Hungary
- Institute of Biophysics, Biological Research Centre, Szeged, Hungary
| | - Florentine Marx
- Institute of Molecular Biology, Biocenter, Medical University of Innsbruck, Innsbruck, Austria
| | - László Galgóczy
- Institute of Plant Biology, Biological Research Centre, Szeged, Hungary
- Department of Biotechnology, Faculty of Science and Informatics, University of Szeged, Szeged, Hungary
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Two small, cysteine-rich and cationic antifungal proteins from Penicillium chrysogenum: A comparative study of PAF and PAFB. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1862:183246. [PMID: 32142818 PMCID: PMC7138148 DOI: 10.1016/j.bbamem.2020.183246] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Revised: 02/06/2020] [Accepted: 02/10/2020] [Indexed: 12/16/2022]
Abstract
The filamentous fungus Penicillium chrysogenum Q176 secretes the antimicrobial proteins (AMPs) PAF and PAFB, which share a compact disulfide-bond mediated, β-fold structure rendering them highly stable. These two AMPs effectively inhibit the growth of human pathogenic fungi in micromolar concentrations and exhibit antiviral potential without causing cytotoxic effects on mammalian cells in vitro and in vivo. The antifungal mechanism of action of both AMPs is closely linked to - but not solely dependent on - the lipid composition of the fungal cell membrane and requires a strictly regulated protein uptake into the cell, indicating that PAF and PAFB are not canonical membrane active proteins. Variations in their antifungal spectrum and their killing dynamics point towards a divergent mode of action related to their physicochemical properties and surface charge distribution. In this review, we relate characteristic features of PAF and PAFB to the current knowledge about other AMPs of different sources. In addition, we present original data that have never been published before to substantiate our assumptions and provide evidences that help to explain and understand better the mechanistic function of PAF and PAFB. Finally, we underline the promising potential of PAF and PAFB as future antifungal therapeutics. Penicillium chrysogenum secretes the small, cysteine-rich proteins PAF and PAFB. Both exhibit antifungal activity, but with differences in their mode of action. Structure, membrane interaction and cellular uptake determine their function. PAF and PAFB are well tolerated by mammalian cells. They promise applicability in medicine, plant protection and food industry.
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Investigation of the effect of transition metals (MN, CO, GD) on the spatial structure of fibrinopeptide B by NMR spectroscopy. J Mol Struct 2020. [DOI: 10.1016/j.molstruc.2019.127484] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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Huber A, Lerchster H, Marx F. Nutrient Excess Triggers the Expression of the Penicillium chrysogenum Antifungal Protein PAFB. Microorganisms 2019; 7:microorganisms7120654. [PMID: 31817241 PMCID: PMC6956099 DOI: 10.3390/microorganisms7120654] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 11/28/2019] [Accepted: 11/29/2019] [Indexed: 12/17/2022] Open
Abstract
Nutrient limitation and nonfavorable growth conditions have been suggested to be major triggers for the expression of small, cysteine-rich antimicrobial proteins (AMPs) of fungal origin, e.g., the Penicillium chrysogenum antifungal protein (PAF), the Aspergillus giganteus antifungal protein (AFP), the Aspergillus niger antifungal protein (AnAFP). Therefore, these AMPs have been considered to be fungal secondary metabolite products. In contrast, the present study revealed that the expression of the PAF-related AMP P. chrysogenum antifungal protein B (PAFB) is strongly induced under nutrient excess during the logarithmic growth phase, whereas PAFB remained under the detection level in the supernatant of cultures grown under nutrient limitation. The efficiency of the pafB-promoter to induce PAFB expression was compared with that of two P. chrysogenum promoters that are well established for recombinant protein production: the paf-promoter and the xylose-inducible promoter of the xylanase gene, xylP. The inducibility of the pafB-promoter was superior to that of the xylP-promoter yielding comparable PAFB amounts as under the regulation of the paf-promoter. We conclude that (i) differences in the expression regulation of AMPs suggest distinct functional roles in the producer beyond their antifungal activity; and (ii) the pafB-promoter is a promising tool for recombinant protein production in P. chrysogenum, as it guarantees strong gene expression with the advantage of inducibility.
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