scholarly journals Structure and Synthesis of Antifungal Disulfide β-Strand Proteins from Filamentous Fungi

2018 ◽  
Vol 7 (1) ◽  
pp. 5 ◽  
Author(s):  
Györgyi Váradi ◽  
Gábor Tóth ◽  
Gyula Batta
Keyword(s):  
Filamentous Fungi ◽  
Disulfide Bonds ◽  
Antimicrobial Agents ◽  
Tertiary Structure ◽  
Fungal Infections ◽  
Recombinant Expression ◽  
Antifungal Protein ◽  
Significant Group ◽  
Antifungal Proteins ◽  
Neosartorya Fischeri

The discovery and understanding of the mode of action of new antimicrobial agents is extremely urgent, since fungal infections cause 1.5 million deaths annually. Antifungal peptides and proteins represent a significant group of compounds that are able to kill pathogenic fungi. Based on phylogenetic analyses the ascomycetous, cysteine-rich antifungal proteins can be divided into three different groups: Penicillium chrysogenum antifungal protein (PAF), Neosartorya fischeri antifungal protein 2 (NFAP2) and “bubble-proteins” (BP) produced, for example, by P. brevicompactum. They all dominantly have β-strand secondary structures that are stabilized by several disulfide bonds. The PAF group (AFP antifungal protein from Aspergillus giganteus, PAF and PAFB from P. chrysogenum, Neosartorya fischeri antifungal protein (NFAP)) is the best characterized with their common β-barrel tertiary structure. These proteins and variants can efficiently be obtained either from fungi production or by recombinant expression. However, chemical synthesis may be a complementary aid for preparing unusual modifications, e.g., the incorporation of non-coded amino acids, fluorophores, or even unnatural disulfide bonds. Synthetic variants up to ca. 6–7 kDa can also be put to good use for corroborating structure determination. A short overview of the structural peculiarities of antifungal β-strand disulfide bridged proteins will be given. Here, we describe the structural propensities of some known antifungal proteins from filamentous fungi which can also be prepared with modern synthetic chemistry methods.

scholarly journals Structural and Gene Characterization of a New Antifungal Peptide Obtained from Penicillium crustosum FP11 Strain

2020 ◽  
pp. 50-60
Author(s):  
Juliana Beal Menegotto ◽  
Lucas F. Ribeiro ◽  
Rita de Cássia Garcia Simão ◽  
Alexandre Maller ◽  
Marina Kimiko Kadowaki ◽  
...  
Keyword(s):  
Disulfide Bonds ◽  
Tertiary Structure ◽  
Antifungal Protein ◽  
Antifungal Peptide ◽  
Potential Candidate ◽  
Mature Peptide ◽  
Motif Analysis ◽  
Core Motif ◽  
Gene Characterization ◽  
Penicillium Crustosum

A novel antifungal peptide, PcAFP (6.48 kDa, pI 8.83), was obtained from the culture supernatant of the fungus Penicillium crustosum. The gene encoding the PcAFP peptide was isolated based on its homologue in Penicillium chrysogenum, PgAFP. PcAFP is a small, cystine-rich peptide, and the mature peptide consists of 58 amino acid residues. The immature P. crustosum antifungal protein (AFP) showed 95.65% identity to the antifungal protein of P. chrysogenum, while the mature peptide showed 98.28% identity with PgAFP. Molecular modeling of the tertiary structure of the mature peptide revealed details of the conserved structure of the AFPs, such as the β-barrel motif stabilized by three disulfide bonds and the l-core motif. Analysis of the extract by 16% tricine SDS-PAGE showed a 6.9 kDa peptide, which was close to the predicted molecular mass of the mature peptide of 6.48 kDa. Assays of antimicrobial activity, performed by broth microdilution using the crude extract obtained from the culture medium, showed activity against Candida albicans. These results demonstrate the conservation of the PcAPF gene and the high level of identity with the PgAFP antifungal protein of P. chrysogenum. Given these structural and biochemical characteristics, PcAFP could be a potential candidate for future investigations that may aid in the development of new antifungal compounds.

Yeast glucoamylases: molecular-genetic and structural characterization

Biologia ◽  
2010 ◽  
Vol 65 (4) ◽  
Author(s):  
Eva Hostinová ◽  
Juraj Gašperík
Keyword(s):  
Filamentous Fungi ◽  
Tertiary Structure ◽  
Biochemical Characterization ◽  
Recombinant Expression ◽  
Molecular Genetic ◽  
Extracellular Enzyme ◽  
Major Application ◽  
The Given

AbstractGlucoamylase is an extracellular enzyme produced mainly by microorganisms. It belongs to the commercially frequently exploited biocatalysts. The major application of glucoamylase is in the starch bioprocessing to produce glucose and in alcoholic fermentations of starchy materials. Filamentous fungi have been the source of glucoamylases for industrial purposes as well as an object of numerous research studies. Some yeasts also secrete a large amount of glucoamylase with biochemical characteristics slightly different from those of filamentous fungi. Modern biotechnological applications require glucoamylases of certain properties optimal for a given process. Novel biocatalysts can be prepared from already existing enzymes using techniques of protein engineering or directed evolution. Tailoring of a commercial glucoamylase requires knowledge, on a molecular level, of structure/function relationships of enzymes originating from various sources and having different catalytic properties. Sequences of the cloned genes, their recombinant expression and the tertiary structure determination of glucoamylase are prerequisite to obtain such information. The presented review focuses on molecular-genetic and structural aspects of yeast glucoamylases, supplemented with the basic biochemical characterization of the given enzymes.

scholarly journals An Antifungal Chitosanase from Bacillus subtilis SH21

Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 1863
Author(s):  
Yuanxiang Pang ◽  
Jianjun Yang ◽  
Xinyue Chen ◽  
Yu Jia ◽  
Tong Li ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Liquid Chromatography ◽  
Tertiary Structure ◽  
Fungal Infections ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Exchange Chromatography ◽  
Antifungal Protein ◽  
Selection Marker ◽  
Ms Analysis

Bacillus subtilis SH21 was observed to produce an antifungal protein that inhibited the growth of F. solani. To purify this protein, ammonium sulfate precipitation, gel filtration chromatography, and ion-exchange chromatography were used. The purity of the purified product was 91.33% according to high-performance liquid chromatography results. Sodium dodecyl sulfate–polyacrylamide gel electrophoresis and liquid chromatography–tandem mass spectrometry (LC–MS/MS) analysis revealed that the molecular weight of the protein is 30.72 kDa. The results of the LC–MS/MS analysis and a subsequent sequence-database search indicated that this protein was a chitosanase, and thus, we named it chitosanase SH21. Scanning and transmission electron microscopy revealed that chitosanase SH21 appeared to inhibit the growth of F. solani by causing hyphal ablation, distortion, or abnormalities, and cell-wall depression. The minimum inhibitory concentration of chitosanase SH21 against F. solani was 68 µg/mL. Subsequently, the corresponding gene was cloned and sequenced, and sequence analysis indicated an open reading frame of 831 bp. The predicted secondary structure indicated that chitosanase SH21 has a typical a-helix from the glycoside hydrolase (GH) 46 family. The tertiary structure shared 40% similarity with that of Streptomyces sp. N174. This study provides a theoretical basis for a topical cream against fungal infections in agriculture and a selection marker on fungi.

Heterocycle Compounds with Antimicrobial Activity

2020 ◽  
Vol 26 (8) ◽  
pp. 867-904 ◽  
Author(s):  
Maria Fesatidou ◽  
Anthi Petrou ◽  
Geronikaki Athina
Keyword(s):  
Heterocyclic Compounds ◽  
Bacterial Infections ◽  
Scientific Community ◽  
Antimicrobial Agents ◽  
Fungal Infections ◽  
Biological Activities ◽  
Literature Survey ◽  
New Findings ◽  
Wide Range ◽  
Number Of Microorganisms

Background: Bacterial infections are a growing problem worldwide causing morbidity and mortality mainly in developing countries. Moreover, the increased number of microorganisms, developing multiple resistances to known drugs, due to abuse of antibiotics, is another serious problem. This problem becomes more serious for immunocompromised patients and those who are often disposed to opportunistic fungal infections. Objective: The objective of this manuscript is to give an overview of new findings in the field of antimicrobial agents among five-membered heterocyclic compounds. These heterocyclic compounds especially five-membered attracted the interest of the scientific community not only for their occurrence in nature but also due to their wide range of biological activities. Method: To reach our goal, a literature survey that covers the last decade was performed. Results: As a result, recent data on the biological activity of thiazole, thiazolidinone, benzothiazole and thiadiazole derivatives are mentioned. Conclusion: It should be mentioned that despite the progress in the development of new antimicrobial agents, there is still room for new findings. Thus, research still continues.

scholarly journals Biosynthesis of Silver Nanoparticles Mediated by Entomopathogenic Fungi: Antimicrobial Resistance, Nanopesticides, and Toxicity

Antibiotics ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 852
Author(s):  
Tárcio S. Santos ◽  
Tarcisio M. Silva ◽  
Juliana C. Cardoso ◽  
Ricardo L. C. de Albuquerque-Júnior ◽  
Aleksandra Zielinska ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Filamentous Fungi ◽  
Entomopathogenic Fungi ◽  
Antimicrobial Agents ◽  
Insect Pests ◽  
Insect Control ◽  
Biological Synthesis ◽  
Biological Methods ◽  
Potential Use

Silver nanoparticles are widely used in the biomedical and agri-food fields due to their versatility. The use of biological methods for the synthesis of silver nanoparticles has increased considerably due to their feasibility and high biocompatibility. In general, microorganisms have been widely explored for the production of silver nanoparticles for several applications. The objective of this work was to evaluate the use of entomopathogenic fungi for the biological synthesis of silver nanoparticles, in comparison to the use of other filamentous fungi, and the possibility of using these nanoparticles as antimicrobial agents and for the control of insect pests. In addition, the in vitro methods commonly used to assess the toxicity of these materials are discussed. Several species of filamentous fungi are known to have the ability to form silver nanoparticles, but few studies have been conducted on the potential of entomopathogenic fungi to produce these materials. The investigation of the toxicity of silver nanoparticles is usually carried out in vitro through cytotoxicity/genotoxicity analyses, using well-established methodologies, such as MTT and comet assays, respectively. The use of silver nanoparticles obtained through entomopathogenic fungi against insects is mainly focused on mosquitoes that transmit diseases to humans, with satisfactory results regarding mortality estimates. Entomopathogenic fungi can be employed in the synthesis of silver nanoparticles for potential use in insect control, but there is a need to expand studies on toxicity so to enable their use also in insect control in agriculture.

scholarly journals Additional disulfide bonds in insulin: Prediction, recombinant expression, receptor binding affinity, and stability

2015 ◽  
Vol 24 (5) ◽  
pp. 779-788 ◽  
Author(s):  
Tine N. Vinther ◽  
Ingrid Pettersson ◽  
Kasper Huus ◽  
Morten Schlein ◽  
Dorte B. Steensgaard ◽  
...  
Keyword(s):  
Binding Affinity ◽  
Receptor Binding ◽  
Disulfide Bonds ◽  
Recombinant Expression ◽  
Receptor Binding Affinity

scholarly journals Bacterial and Fungal Co-infections with SARS-CoV-2 in Solid Organ Recipients, A Retrospective Study

2021 ◽  
Author(s):  
Mojtaba Shafiekhani ◽  
Zahra Shekari ◽  
Arash Boorboor ◽  
Zahra Zare ◽  
Sara Arabsheybani ◽  
...  
Keyword(s):  
Antimicrobial Agents ◽  
Fungal Infections ◽  
Binary Logistic Regression ◽  
Risk Groups ◽  
Solid Organ ◽  
Binary Logistic Regression Model ◽  
Kidney Recipients ◽  
Susceptible Patient ◽  
Liver And Kidney ◽  
Vancomycin Resistant

Abstract Background SARS-CoV-2, a novel corona virus, has caused clusters of fatal pneumonia worldwide. Immune compromised patients are among the high risk groups with poor prognosis of the disease. The presence of bacterial or fungal co-infections with SARS-CoV-2 is associated with increased mortality.Methods The electronic data of the liver and kidney recipients, hospitalized in COVID-19 intensive care unit in an 8-month period in 2020 were retrospectively assessed. The documented bacterial or fungal infections alongside with outcome and risk factors were recorded and analyzed by binary logistic regression model and multivariate analyses.Results Sixty-Six liver and kidney recipients were included this study. Twenty one percent of the patients had at least one episode of co-infection during their COVID-19 course. Bacterial and fungal co-infections contributed to a significantly higher mortality. Urine and sputum were the most common sites of pathogen isolation (45.45 % and 36.36%; respectively). The majority of infections were caused by vancomycin- resistant Enterococci (30%). Escherichia coli stood in the next position with 23.3%. Prior hospitalization and high does corticosteroid use were associated with co-infections (p=0<0.001 and p=0.02; respectively.)Conclusions Bacterial and fungal co-infections with COVID-19 are more prevalent on solid organ recipients compared to the general population. Prior hospitalizations and use of broad-spectrum antimicrobial agents leads to emergence of multi-drug resistant pathogens in this susceptible patient population. Early detection and treatment of co-infections as well as antibiotic stewardship is recommended in solid organ recipients.

Studies on the aerobic deterioration of whole-crop cereal silages

1982 ◽  
Vol 98 (3) ◽  
pp. 529-535 ◽  
Author(s):  
M. K. Woolford ◽  
K. K. Bolsen ◽  
Lesley A. Peartt
Keyword(s):  
Filamentous Fungi ◽  
Butyric Acid ◽  
Dry Matter ◽  
Antimicrobial Agents ◽  
Matter Content ◽  
Dry Matter Content ◽  
Antimicrobial Effects ◽  
High Dry Matter ◽  
Proteolytic Bacteria ◽  
Barley Silage

SUMMARYAs a result of the treatment of made whole-crop barley silage with antimicrobial agents which are specifically inhibitory to fungi or bacteria, it was shown that the subsequent aerobic deterioration was essentially caused by yeasts. These microorganisms were instrumental in the rise in pH, the increase in temperature and the loss of dry matter observed. The filamentous fungi, like one group of bacteria (the streptomycetes), apparently had no part in the process. Bacteria, such as the lactobacilli and particularly proteolytic bacteria, may have had a role in the terminal stages of deterioration, although it was considered more likely that the yeasts again were involved.The whole-crop wheat silage employed in this work was stable in air, a factor attributed to the combined antimicrobial effects of butyric acid present and the relatively high dry-matter content.

Candidiasis

2018 ◽  
Author(s):  
Brett A Melnikoff ◽  
René P Myers
Keyword(s):  
Critically Ill ◽  
Critically Ill Patients ◽  
Antimicrobial Agents ◽  
Fungal Infections ◽  
Diagnostic Methods ◽  
Ventricular Assist Devices ◽  
Transplant Recipients ◽  
Ventricular Assist ◽  
Disseminated Candidiasis ◽  
Candida Infections

Fungal infections remain an important cause of morbidity and mortality in surgical settings, with critically ill patients, transplant recipients, and sick neonates all especially vulnerable. Over the past few decades, technological and scientific advancements have improved physicians’ ability to sustain life in critically ill patients; developments in chemotherapeutics and immune-based therapies have yielded increased survival for many cancer patients; organ transplantation has evolved dramatically; and the use of invasive therapies (eg, ventricular assist devices) has increased markedly. With these changes has come an increase in the incidence of serious Candida infections. This review covers the definition and classification, epidemiology and risk factors, and clinical evaluation of candidiasis, as well as management of candidemia, acute disseminated candidiasis, nonhematogenous candidiasis, and peritonitis and intra-abdominal abscess. Figures show Candida endophthalmitis in patients with persistent fungemia and superficial candidiasis in the gastrointestinal tract. Tables list clinical presentation and diagnostic methods for common fungal infections, antimicrobial agents of choice for candidal infections, and the latest guidelines for candidiasis. This review contains 2 figures, 3 tables and 131 references Key words: acute disseminated candidiasis, candidemia, candidiasis, candiduria, nonhematogenous candidiasis  

scholarly journals A Novel Secreted Cysteine-Rich Anionic (Sca) Protein from the Citrus Postharvest Pathogen Penicillium digitatum Enhances Virulence and Modulates the Activity of the Antifungal Protein B (AfpB)

2020 ◽  
Vol 6 (4) ◽  
pp. 203
Author(s):  
Sandra Garrigues ◽  
Jose F. Marcos ◽  
Paloma Manzanares ◽  
Mónica Gandía
Keyword(s):  
Citrus Fruit ◽  
Penicillium Digitatum ◽  
Antifungal Protein ◽  
Penicillium Expansum ◽  
Wild Type ◽  
Phenotypic Differences ◽  
Antifungal Proteins ◽  
Ascomycete Fungi ◽  
In Vitro Antifungal Activity

Antifungal proteins (AFPs) from ascomycete fungi could help the development of antimycotics. However, little is known about their biological role or functional interactions with other fungal biomolecules. We previously reported that AfpB from the postharvest pathogen Penicillium digitatum cannot be detected in the parental fungus yet is abundantly produced biotechnologically. While aiming to detect AfpB, we identified a conserved and novel small Secreted Cysteine-rich Anionic (Sca) protein, encoded by the gene PDIG_23520 from P. digitatum CECT 20796. The sca gene is expressed during culture and early during citrus fruit infection. Both null mutant (Δsca) and Sca overproducer (Scaop) strains show no phenotypic differences from the wild type. Sca is not antimicrobial but potentiates P. digitatum growth when added in high amounts and enhances the in vitro antifungal activity of AfpB. The Scaop strain shows increased incidence of infection in citrus fruit, similar to the addition of purified Sca to the wild-type inoculum. Sca compensates and overcomes the protective effect of AfpB and the antifungal protein PeAfpA from the apple pathogen Penicillium expansum in fruit inoculations. Our study shows that Sca is a novel protein that enhances the growth and virulence of its parental fungus and modulates the activity of AFPs.

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