scholarly journals Isolation of Fungal Cell Wall Degrading Proteins from Barley (Hordeum vulgare L.) Leaves Infected with Rhynchosporium secalis

2002 ◽  
Vol 15 (10) ◽  
pp. 1031-1039 ◽  
Author(s):  
Reza Zareie ◽  
Dara L. Melanson ◽  
Peter J. Murphy
Keyword(s):  
Cell Wall ◽  
Antifungal Activity ◽  
Plant Disease Resistance ◽  
High Performance ◽  
Peptide Mapping ◽  
Rhynchosporium Secalis ◽  
Active Components ◽  
Hordeum Vulgare L ◽  
Fungal Cell ◽  
Barley Leaves

Proteins with antifungal activity towards Rhynchosporium secalis conidia were isolated from the intercellular washing fluid (IWF) of barley leaves. The active components were purified by high-performance liquid chromatography under conditions that maintained biological activity. Five major barley IWF proteins deleterious to the cell wall of viable R. secalis conidia were isolated and identified by a combination of N-terminal amino acid sequencing, peptide mapping, and determination of mass and isoelectric point. They were a 32-kDa β-1,3-glucanase (Pr32), a 25-kDa chitinase (Pr25), and three 22-kDa thaumatin-like (TL) proteins (Pr22-1, Pr22-2, and Pr22-3). Pr22-1 and Pr22-2 were similar to the protein R class of TL proteins, whereas Pr22-3 was more similar to the S class. Pr22-3 was shown to digest laminarin, indicating that this TL protein has glucanase activity. In addition, Pr22-3 was more active in the spore bioassay than Pr22-2. Various combinations of the five proteins had a greater effect on R. secalis spores than did the individual proteins. The extraction of proteins with antifungal activity from the IWF of barley leaves indicates their possible role in defense against leaf pathogens. A similar bioassay may be developed for other systems to identify particular isoforms of pathogenicity-related proteins that might have a role in plant disease resistance.

scholarly journals The newly synthesized thiazole derivatives as potential antifungal compounds against Candida albicans

2021 ◽  
Author(s):  
Anna Biernasiuk ◽  
Anna Berecka-Rycerz ◽  
Anna Gumieniczek ◽  
Maria Malm ◽  
Krzysztof Z. Łączkowski ◽  
...  
Keyword(s):  
Cell Wall ◽  
Candida Albicans ◽  
Antifungal Activity ◽  
Cell Membrane ◽  
Mode Of Action ◽  
Thiazole Derivatives ◽  
Fungal Cell ◽  
Erythrocyte Lysis ◽  
Low Cytotoxicity ◽  
High Antifungal Activity

Abstract Recently, the occurrence of candidiasis has increased dramatically, especially in immunocompromised patients. Additionally, their treatment is often ineffective due to the resistance of yeasts to antimycotics. Therefore, there is a need to search for new antifungals. A series of nine newly synthesized thiazole derivatives containing the cyclopropane system, showing promising activity against Candida spp., has been further investigated. We decided to verify their antifungal activity towards clinical Candida albicans isolated from the oral cavity of patients with hematological malignancies and investigate the mode of action on fungal cell, the effect of combination with the selected antimycotics, toxicity to erythrocytes, and lipophilicity. These studies were performed by the broth microdilution method, test with sorbitol and ergosterol, checkerboard technique, erythrocyte lysis assay, and reversed phase thin-layer chromatography, respectively. All derivatives showed very strong activity (similar and even higher than nystatin) against all C. albicans isolates with minimal inhibitory concentration (MIC) = 0.008–7.81 µg/mL Their mechanism of action may be related to action within the fungal cell wall structure and/or within the cell membrane. The interactions between the derivatives and the selected antimycotics (nystatin, chlorhexidine, and thymol) showed additive effect only in the case of combination some of them and thymol. The erythrocyte lysis assay confirmed the low cytotoxicity of these compounds as compared to nystatin. The high lipophilicity of the derivatives was related with their high antifungal activity. The present studies confirm that the studied thiazole derivatives containing the cyclopropane system appear to be a very promising group of compounds in treatment of infections caused by C. albicans. However, this requires further studies in vivo. Key points • The newly thiazoles showed high antifungal activity and some of them — additive effect in combination with thymol. • Their mode of action may be related with the influence on the structure of the fungal cell wall and/or the cell membrane. • The low cytotoxicity against erythrocytes and high lipophilicity of these derivatives are their additional good properties. Graphical abstract

scholarly journals Screening and Antifungal Activity of a β-Carboline Derivative against Cryptococcus neoformans and C. gattii

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Kátia Santana Cruz ◽  
Emerson Silva Lima ◽  
Marcia de Jesus Amazonas da Silva ◽  
Erica Simplício de Souza ◽  
Andreia Montoia ◽  
...  
Keyword(s):  
Cell Wall ◽  
Candida Albicans ◽  
Antifungal Activity ◽  
Cryptococcus Neoformans ◽  
Active Compound ◽  
Cell Walls ◽  
Human Fibroblasts ◽  
Lead Compound ◽  
Fungal Cell ◽  
Fungal Cell Walls

Background. Cryptococcosis is a fungal disease of bad prognosis due to its pathogenicity and the toxicity of the drugs used for its treatment. The aim of this study was to investigate the medicinal potential of carbazole and β-carboline alkaloids and derivatives against Cryptococcus neoformans and C. gattii. Methods. MICs were established in accordance with the recommendations of the Clinical and Laboratory Standards Institute for alkaloids and derivatives against C. neoformans and C. gattii genotypes VNI and VGI, respectively. A single active compound was further evaluated against C. neoformans genotypes VNII, VNIII, and VNIV, C. gattii genotypes VGI, VGIII, and VGIV, Candida albicans ATCC 36232, for cytotoxicity against the MRC-5 lineage of human fibroblasts and for effects on fungal cells (cell wall, ergosterol, and leakage of nucleic acids). Results. Screening of 11 compounds revealed 8-nitroharmane as a significant inhibitor (MIC 40 μg/mL) of several C. neoformans and C. gattii genotypes. It was not toxic to fibroblasts (IC50 > 50 µg/mL) nor did it alter fungal cell walls or the concentration of ergosterol in C. albicans or C. neoformans. It increased leakage of substances that absorb at 260 nm. Conclusions. The synthetic β-carboline 8-nitroharmane significantly inhibits pathogenic Cryptococcus species and is interesting as a lead compound towards new therapy for Cryptococcus infections.

scholarly journals Human Antibodies against a Purified Glucosylceramide from Cryptococcus neoformans Inhibit Cell Budding and Fungal Growth

2000 ◽  
Vol 68 (12) ◽  
pp. 7049-7060 ◽  
Author(s):  
Marcio L. Rodrigues ◽  
Luiz R. Travassos ◽  
Kildare R. Miranda ◽  
Anderson J. Franzen ◽  
Sonia Rozental ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Cell Wall ◽  
Cryptococcus Neoformans ◽  
High Performance ◽  
Fungal Growth ◽  
Fungal Cell ◽  
Human Antibodies ◽  
Different Strains ◽  
Immunofluorescence Labeling

ABSTRACT A major ceramide monohexoside (CMH) was purified from lipidic extracts of Cryptococcus neoformans. This molecule was analyzed by high-performance thin-layer chromatography (HPTLC), gas chromatography coupled with mass spectrometry, and fast atom bombardment-mass spectrometry. The cryptococcal CMH is a β-glucosylceramide, with the carbohydrate residue attached to 9-methyl-4,8-sphingadienine in amidic linkage to 2-hydroxyoctadecanoic acid. Sera from patients with cryptococcosis and a few other mycoses reacted with the cryptococcal CMH. Specific antibodies were purified from patients' sera by immunoadsorption on the purified glycolipid followed by protein G affinity chromatography. The purified antibodies to CMH (mainly immunoglobulin G1) bound to different strains and serological types of C. neoformans, as shown by flow cytofluorimetry and immunofluorescence labeling. Transmission electron microscopy of yeasts labeled with immunogold-antibodies to CMH and immunostaining of isolated cell wall lipid extracts separated by HPTLC showed that the cryptococcal CMH predominantly localizes to the fungal cell wall. Confocal microscopy revealed that the β-glucosylceramide accumulates mostly at the budding sites of dividing cells with a more disperse distribution at the cell surface of nondividing cells. The increased density of sphingolipid molecules seems to correlate with thickening of the cell wall, hence with its biosynthesis. The addition of human antibodies to CMH to cryptococcal cultures of both acapsular and encapsulated strains of C. neoformans inhibited cell budding and cell growth. This process was complement-independent and reversible upon removal of the antibodies. The present data suggest that the cryptococcal β-glucosylceramide is a fungal antigen that plays a role on the cell wall synthesis and yeast budding and that antibodies raised against this component are inhibitory in vitro.

scholarly journals Antifungal Activity against Botrytis cinerea of 2,6-Dimethoxy-4-(phenylimino)cyclohexa-2,5-dienone Derivatives

Molecules ◽  
2019 ◽  
Vol 24 (4) ◽  
pp. 706 ◽  
Author(s):  
Paulo Castro ◽  
Leonora Mendoza ◽  
Claudio Vásquez ◽  
Paz Pereira ◽  
Freddy Navarro ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Cell Wall ◽  
Antifungal Activity ◽  
Botrytis Cinerea ◽  
Aromatic Ring ◽  
13C Nmr ◽  
Trametes Versicolor ◽  
Fungal Cell Wall ◽  
Fungal Cell ◽  
1H And 13C Nmr

In this work the enzyme laccase from Trametes versicolor was used to synthetize 2,6-dimethoxy-4-(phenylimino)cyclohexa-2,5-dienone derivatives. Ten products with different substitutions in the aromatic ring were synthetized and characterized using 1H- and 13C-NMR and mass spectrometry. The 3,5-dichlorinated compound showed highest antifungal activity against the phytopathogen Botrytis cinerea, while the p-methoxylated compound had the lowest activity; however, the antifungal activity of the products was higher than the activity of the substrates of the reactions. Finally, the results suggested that these compounds produced damage in the fungal cell wall.

scholarly journals An oligosaccharide analog exhibited antifungal activity by misleading cell wall organization via targeting PHR transglucosidases

2021 ◽  
Author(s):  
Ruilian Li ◽  
Zhuo Wang ◽  
Limeng Zhu ◽  
Dongdong Liu ◽  
Wenjing Wang ◽  
...  
Keyword(s):  
Cell Wall ◽  
Antifungal Activity ◽  
Antifungal Drugs ◽  
Chitosan Oligosaccharide ◽  
Synergistic Activity ◽  
Cell Wall Polysaccharide ◽  
Cell Wall Polysaccharides ◽  
Fungal Cell ◽  
Cell Wall Organization ◽  
Dynamic Cell

The fungal cell wall is an ideal target for the design of antifungal drugs. In this study we used an analog of cell wall polymer, a highly deacetylated long-chain chitosan oligosaccharide (HCOS), to test its effect against pathogenic Candida strains. Results showed that HCOS was successfully incorporated into the dynamic cell wall organization process and exhibited an apparent antifungal activity against both plankton and mature fungal biofilm, by impairing the cell wall integrity. Unexpectedly, mechanistic studies suggested that HCOS exerts its activity by interfering with family members of PHR β-(1,3)-glucanosyl transferases and affecting the connection and assembly of cell wall polysaccharides. Furthermore, HCOS showed great synergistic activity with different fungicides against Candida cells, especially those in biofilm. These findings indicated HCOS has a great potential as an antifungal drug or drug synergist and proposed a novel antifungal strategy with structure-specific oligosaccharides mimicking cell wall polysaccharide fragments.

scholarly journals MoGLN2 Is Important for Vegetative Growth, Conidiogenesis, Maintenance of Cell Wall Integrity and Pathogenesis of Magnaporthe oryzae

2021 ◽  
Vol 7 (6) ◽  
pp. 463
Author(s):  
Osakina Aron ◽  
Min Wang ◽  
Lianyu Lin ◽  
Wajjiha Batool ◽  
Birong Lin ◽  
...  
Keyword(s):  
Cell Wall ◽  
Amino Acid ◽  
Glutamine Synthetase ◽  
Magnaporthe Oryzae ◽  
Vegetative Growth ◽  
Fungal Pathogens ◽  
Cell Wall Integrity ◽  
Fungal Cell ◽  
Barley Leaves ◽  
Living Organisms

Glutamine is a non-essential amino acid that acts as a principal source of nitrogen and nucleic acid biosynthesis in living organisms. In Saccharomyces cerevisiae, glutamine synthetase catalyzes the synthesis of glutamine. To determine the role of glutamine synthetase in the development and pathogenicity of plant fungal pathogens, we used S. cerevisiae Gln1 amino acid sequence to identify its orthologs in Magnaporthe oryzae and named them MoGln1, MoGln2, and MoGln3. Deletion of MoGLN1 and MoGLN3 showed that they are not involved in the development and pathogenesis of M. oryzae. Conversely, ∆Mogln2 was reduced in vegetative growth, experienced attenuated growth on Minimal Medium (MM), and exhibited hyphal autolysis on oatmeal and straw decoction and corn media. Exogenous l-glutamine rescued the growth of ∆Mogln2 on MM. The ∆Mogln2 mutant failed to produce spores and was nonpathogenic on barley leaves, as it was unable to form an appressorium-like structure from its hyphal tips. Furthermore, deletion of MoGLN2 altered the fungal cell wall integrity, with the ∆Mogln2 mutant being hypersensitive to H2O2. MoGln1, MoGln2, and MoGln3 are located in the cytoplasm. Taken together, our results shows that MoGLN2 is important for vegetative growth, conidiation, appressorium formation, maintenance of cell wall integrity, oxidative stress tolerance and pathogenesis of M. oryzae.

In vitro antifungal activity of new series of homoallylamines and related compounds with inhibitory properties of the synthesis of fungal cell wall polymers

2003 ◽  
Vol 11 (7) ◽  
pp. 1531-1550 ◽  
Author(s):  
Leonor Y Vargas M ◽  
Marı́a V Castelli ◽  
Vladimir V Kouznetsov ◽  
Juan M Urbina G ◽  
Silvia N López ◽  
...  
Keyword(s):  
Cell Wall ◽  
Antifungal Activity ◽  
Fungal Cell Wall ◽  
Fungal Cell ◽  
Cell Wall Polymers ◽  
Related Compounds ◽  
In Vitro Antifungal Activity

scholarly journals Kemampuan Kitinase Streptomyces RKt5 sebagai Antijamur terhadap Patogen Fusarium oxysporum

2012 ◽  
Vol 14 (1) ◽  
pp. 42
Author(s):  
Yurnaliza Yurnaliza ◽  
Sebastian Margino ◽  
Langkah Sembiring
Keyword(s):  
Cell Wall ◽  
Antifungal Activity ◽  
Incubation Time ◽  
Mycelial Growth ◽  
Fungal Growth ◽  
Dual Culture ◽  
Optimum Conditions ◽  
Fungal Cell ◽  
Inoculum Concentration ◽  
Cell Wall Lysis

The purpose of the reasearch is to determine of antifungal activity from chitinase from Streptomyces RKt5 to inhibite growth of Fusariumoxysporum. The chitinase of Streptomyces RKt5 produced in liquid chitin medium with optimum conditions (inoculum concentration, pHand incubation time) and then partially purified with ammonium sulphate. The enzyme products were tested the antifungal activity againstF.oxysporum. The results showed that mycelial growth of F.oxysporum can be inhibited by Streptomyces RKt 5 in dual culture test. Thepartial purified chitinase enzyme couldn’t inhibit the fungal growth. But if the mycellium fragmented, the enzyme could degrade the fungalcell wall in incubation time. The frequency of fungal cell wall lysis and levels of N-acetylglucosamine released that have been increasingalong with the length of incubation time.

scholarly journals The response regulator Skn7 of Aspergillus fumigatus is essential for the antifungal effect of fludioxonil

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sebastian Schruefer ◽  
Isabella Böhmer ◽  
Karl Dichtl ◽  
Anja Spadinger ◽  
Christoph Kleinemeier ◽  
...  
Keyword(s):  
Cell Wall ◽  
Antifungal Activity ◽  
Aspergillus Fumigatus ◽  
Osmotic Pressure ◽  
Response Regulator ◽  
Treatment Options ◽  
Glycerol Concentration ◽  
Hog Pathway ◽  
Calcofluor White ◽  
Fungal Cell

AbstractAspergillus fumigatus is an important fungal pathogen that represents a major threat for severely immunocompromised patients. Cases of invasive aspergillosis are associated with a high mortality rate, which reflects the limited treatment options that are currently available. The development of novel therapeutic approaches is therefore an urgent task. An interesting compound is fludioxonil, a derivative of the bacterial secondary metabolite pyrrolnitrin. Both agents possess potent antimicrobial activity against A. fumigatus and trigger a lethal activation of the group III hybrid histidine kinase TcsC, the major sensor kinase of the High Osmolarity Glycerol (HOG) pathway in A. fumigatus. In the current study, we have characterized proteins that operate downstream of TcsC and analyzed their roles in the antifungal activity of fludioxonil and in other stress situations. We found that the SskA-SakA axis of the HOG pathway and Skn7 can independently induce an increase of the internal glycerol concentration, but each of these individual responses amounts for only half of the level found in the wild type. The lethal fludioxonil-induced ballooning occurs in the sskA and the sakA mutant, but not in the skn7-deficient strain, although all three strains show comparable glycerol responses. This indicates that an elevated osmotic pressure is necessary, but not sufficient and that a second, decisive and Skn7-dependent mechanism mediates the antifungal activity. We assume that fludioxonil triggers a reorganization in the fungal cell wall that reduces its rigidity, which in combination with the elevated osmotic pressure executes the lethal expansion of the fungal cells. Two findings link Skn7 to the cell wall of A. fumigatus: (1) the fludioxonil-induced massive increase in the chitin content depends on Skn7 and (2) the skn7 mutant is more resistant to the cell wall stressor Calcofluor white. In conclusion, our data suggest that the antifungal activity of fludioxonil in A. fumigatus relies on two distinct and synergistic processes: A high internal osmotic pressure and a weakened cell wall. The involvement of Skn7 in both processes most likely accounts for its particular importance in the antifungal activity of fludioxonil.

Sign in / Sign up

Export Citation Format

Share Document