Crystal structure of a Cu,Zn superoxide dismutase from the thermophilic fungus Chaetomium thermophilum

2021 ◽  
Vol 28 ◽  
Author(s):  
Imran Mohsin ◽  
Li-Qing Zhang ◽  
Duo-Chuan Li ◽  
Anastassios C. Papageorgiou
Keyword(s):  
Crystal Structure ◽  
Thermophilic Fungus ◽  
Diffusion Method ◽  
Superoxide Dismutases ◽  
Therapeutic Effects ◽  
Thermophilic Fungi ◽  
Contributing Factors ◽  
Thermostable Enzymes ◽  
Chaetomium Thermophilum ◽  
Promising Source

Background: Thermophilic fungi have recently emerged as a promising source of thermostable enzymes. Superoxide dismutases are key antioxidant metalloenzymes with promising therapeutic effects in various diseases, both acute and chronic. However, structural heterogeneity and low thermostability limit their therapeutic efficacy. Objective: Although several studies from hypethermophilic superoxide dismutases (SODs) have been reported, information about Cu,Zn-SODs from thermophilic fungi is scarce. Chaetomium thermophilum is a thermophilic fungus that could provide proteins with thermophilic properties. Method: The enzyme was expressed in Pichia pastoris cells and crystallized using the vapor-diffusion method. X-ray data were collected, and the structure was determined and refined to 1.56 Å resolution. Structural analysis and comparisons were carried out. Results: The presence of 8 molecules (A through H) in the asymmetric unit resulted in four different interfaces. Molecules A and F form the typical homodimer which is also found in other Cu,Zn-SODs. Zinc was present in all subunits of the structure while copper was found in only four subunits with reduced occupancy (C, D, E and F). Conclusion: The ability of the enzyme to form oligomers and the elevated Thr:Ser ratio may be contributing factors to its thermal stability. Two hydrophobic residues that participate in interface formation and are not present in other CuZn-SODs may play a role in the formation of new interfaces and the oligomerization process. The CtSOD crystal structure reported here is the first Cu,Zn-SOD structure from a thermophilic fungus.

scholarly journals Crystal Structure of a GH3 β-Glucosidase from the Thermophilic Fungus Chaetomium thermophilum

2019 ◽  
Vol 20 (23) ◽  
pp. 5962 ◽  
Author(s):  
Imran Mohsin ◽  
Nirmal Poudel ◽  
Duo-Chuan Li ◽  
Anastassios C. Papageorgiou
Keyword(s):  
Crystal Structure ◽  
Elevated Temperatures ◽  
Cellulose Degradation ◽  
Thermophilic Fungus ◽  
Biofuel Production ◽  
Lignocellulose Degradation ◽  
Thermophilic Fungi ◽  
Biotechnological Applications ◽  
Chaetomium Thermophilum ◽  
Promising Source

Beta-glucosidases (β-glucosidases) have attracted considerable attention in recent years for use in various biotechnological applications. They are also essential enzymes for lignocellulose degradation in biofuel production. However, cost-effective biomass conversion requires the use of highly efficient enzymes. Thus, the search for new enzymes as better alternatives of the currently available enzyme preparations is highly important. Thermophilic fungi are nowadays considered as a promising source of enzymes with improved stability. Here, the crystal structure of a family GH3 β-glucosidase from the thermophilic fungus Chaetomium thermophilum (CtBGL) was determined at a resolution of 2.99 Å. The structure showed the three-domain architecture found in other β-glucosidases with variations in loops and linker regions. The active site catalytic residues in CtBGL were identified as Asp287 (nucleophile) and Glu517 (acid/base). Structural comparison of CtBGL with Protein Data Bank (PDB)-deposited structures revealed variations among glycosylated Asn residues. The enzyme displayed moderate glycosylation compared to other GH3 family β-glucosidases with similar structure. A new glycosylation site at position Asn504 was identified in CtBGL. Moreover, comparison with respect to several thermostability parameters suggested that glycosylation and charged residues involved in electrostatic interactions may contribute to the stability of the enzyme at elevated temperatures. The reported CtBGL structure provides additional insights into the family GH3 enzymes and could offer new ideas for further improvements in β-glucosidases for more efficient use in biotechnological applications regarding cellulose degradation.

scholarly journals X-ray structure analysis of a unique D-amino-acid oxidase from the thermophilic fungus Rasamsonia emersonii strain YA

2020 ◽  
Vol 76 (11) ◽  
pp. 517-523
Author(s):  
Yuya Shimekake ◽  
Yuki Hirato ◽  
Rikako Funabashi ◽  
Sayoko Okazaki ◽  
Masaru Goto ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Thermal Stability ◽  
Amino Acids ◽  
Amino Acid ◽  
Disulfide Bond ◽  
Thermophilic Fungus ◽  
Diffusion Method ◽  
Acid Oxidase ◽  
Amino Acid Oxidase ◽  
Intramolecular Disulfide Bond

D-Amino-acid oxidases (DAAOs) catalyze the oxidative deamination of neutral and basic D-amino acids. The DAAO from the thermophilic fungus Rasamsonia emersonii strain YA (ReDAAO) has a high thermal stability and a unique broad substrate specificity that includes the acidic D-amino acid D-Glu as well as various neutral and basic D-amino acids. In this study, ReDAAO was crystallized by the hanging-drop vapor-diffusion method and its crystal structure was determined at a resolution of 2.00 Å. The crystal structure of the enzyme revealed that unlike other DAAOs, ReDAAO forms a homotetramer and contains an intramolecular disulfide bond (Cys230–Cys285), suggesting that this disulfide bond is involved in the higher thermal stability of ReDAAO. Moreover, the structure of the active site and its vicinity in ReDAAO indicates that Arg97, Lys99, Lys114 and Ser231 are candidates for recognizing the side chain of D-Glu.

scholarly journals Validating Anti-Infective Activity of Pleurotus Opuntiae via Standardization of Its Bioactive Mycoconstituents through Multimodal Biochemical Approach

Coatings ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 484
Author(s):  
Aprajita Tiwari Pandey ◽  
Ishan Pandey ◽  
Anurag Kanase ◽  
Amita Verma ◽  
Beatriz Garcia-Canibano ◽  
...  
Keyword(s):  
Bioactive Compounds ◽  
High Performance ◽  
Colorimetric Assay ◽  
Diffusion Method ◽  
Therapeutic Effects ◽  
Medication Regimen ◽  
Methanol Extracts ◽  
Retention Factors ◽  
Before And After ◽  
Solvent Systems

Mushrooms produce a variety of bioactive compounds that are known to have anti-pathogenic properties with safer and effective therapeutic effects in human disease prognosis. The antibacterial activity of ethanol and methanol extracts of Pleurotus opuntiae were checked against pathogenic microorganisms viz. Pseudomonas aeruginosa ATCC 27853, Proteus mirabilis NCIM 2300, Proteus vulgaris NCIM 5266, Serratia marcescens NCIM 2078, Shigella flexeneri NCIM 5265, Moraxella sp. NCIM 2795, Staphylococcus aureus ATCC 25923 by agar well diffusion method at different concentrations of the extracts. Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) of the extracts was determined by INT (Iodonitrotetrazolium chloride) colorimetric assay. Extracts were standardized by thin layer chromatography (TLC) in different solvent systems. The Retention factors (Rf) of different compounds were calculated by high performance TLC (HPTLC) fingerprinting at UV 254, 366, and 540 nm before and after derivatization. The ethanol and methanol extracts of P. opuntiae showed bactericidal activity against all the test pathogens at MIC values of 15.6 to 52.08 mg/mL and 20.81 to 52.08 mg/mL respectively. Whereas the MBC values for ethanol and methanol extract of P. opuntiae against all pathogens were recorded as 26.03 to 62.5 mg/mL and 125 mg/mL respectively. Preliminary mycochemical screening of both the extracts revealed high contents of bioactive compounds. Amongst all the solvent systems used in TLC, the best result was given by chloroform + hexane (8:2) which eluted out 5 different compounds (spots). HPTLC results revealed spots with different Rf values for all the 24 compounds present. Thus, it can be inferred from the present investigation that the mycoconstituents could be an alternative medication regimen and could play a role in new drug discoveries against different infections. Further, the antimicrobial components of these mushrooms can be transformed to bioengineered antimicrobial coatings for surfaces, drug and other hybrid systems for public health implications in combating persistent infections.

Regenerating Damaged Myocardium: A Review of Stem-Cell Therapies for Heart Failure

2021 ◽  
Author(s):  
Dihan Fan ◽  
Hanrong Wu ◽  
Huashan Peng ◽  
Kaichao Pan ◽  
Rongxue Wu
Keyword(s):  
Drug Testing ◽  
Cardiac Myocyte ◽  
Cardiac Fibroblasts ◽  
Heart Diseases ◽  
Contributing Factors ◽  
Myocardial Repair ◽  
Cardiovascular Research ◽  
Cell Therapies ◽  
Induced Pluripotent ◽  
Promising Source

Cardiovascular disease (CVD) is one of the contributing factors to more than one-third of human mortality and the leading cause of death worldwide. Cardiac myocyte death is a fundamental process in cardiac pathologies caused by various heart diseases, including myocardial infarction. Thus, strategies for replacing fibrotic tissue in the infarcted region with functional myocardium have long been a goal of cardiovascular research. This review focuses primarily on induced-pluripotent stem cells (iPSCs), which have emerged as perhaps the most promising source of cardiomyocytes for both therapeutic applications and drug testing. We also briefly summarize other stems- and progenitor-cell populations that have been used for regenerative myocardial therapy and attempt to generate cardiomyocytes directly from cardiac fibroblasts (i.e., transdifferentiation), which, if successful, may enable the pool of endogenous cardiac fibroblasts to be used as an in-situ source of cardiomyocytes for myocardial repair.

Characterization of a new acidic NAD + -dependent formate dehydrogenase from thermophilic fungus Chaetomium thermophilum

2015 ◽  
Vol 122 ◽  
pp. 212-217 ◽  
Author(s):  
Gülſah ÿzgün ◽  
Nevin Gül Karagüler ◽  
Ossi Turunen ◽  
Nicholas J. Turner ◽  
Barıſ Binay
Keyword(s):  
Formate Dehydrogenase ◽  
Thermophilic Fungus ◽  
Chaetomium Thermophilum

scholarly journals Efficient Plant Biomass Degradation by Thermophilic Fungus Myceliophthora heterothallica

2012 ◽  
Vol 79 (4) ◽  
pp. 1316-1324 ◽  
Author(s):  
Joost van den Brink ◽  
Gonny C. J. van Muiswinkel ◽  
Bart Theelen ◽  
Sandra W. A. Hinz ◽  
Ronald P. de Vries
Keyword(s):  
Wheat Straw ◽  
Plant Biomass ◽  
Hydrolytic Enzymes ◽  
Reaction Times ◽  
Giant Reed ◽  
Thermophilic Fungi ◽  
Biomass Degradation ◽  
Thermostable Enzymes ◽  
Content Type

ABSTRACTRapid and efficient enzymatic degradation of plant biomass into fermentable sugars is a major challenge for the sustainable production of biochemicals and biofuels. Enzymes that are more thermostable (up to 70°C) use shorter reaction times for the complete saccharification of plant polysaccharides compared to hydrolytic enzymes of mesophilic fungi such asTrichodermaandAspergillusspecies. The genusMyceliophthoracontains four thermophilic fungi producing industrially relevant thermostable enzymes. Within this genus, isolates belonging toM. heterothallicawere recently separated from the well-described speciesM. thermophila. We evaluate here the potential ofM. heterothallicaisolates to produce efficient enzyme mixtures for biomass degradation. Compared to the other thermophilicMyceliophthoraspecies, isolates belonging toM. heterothallicaandM. thermophilagrew faster on pretreated spruce, wheat straw, and giant reed. According to their protein profiles andin vitroassays after growth on wheat straw, (hemi-)cellulolytic activities differed strongly betweenM. thermophilaandM. heterothallicaisolates. Compared toM. thermophila,M. heterothallicaisolates were better in releasing sugars from mildly pretreated wheat straw (with 5% HCl) with a high content of xylan. The high levels of residual xylobiose revealed that enzyme mixtures ofMyceliophthoraspecies lack sufficient β-xylosidase activity. Sexual crossing of twoM. heterothallicashowed that progenies had a large genetic and physiological diversity. In the future, this will allow further improvement of the plant biomass-degrading enzyme mixtures ofM. heterothallica.

scholarly journals Regenerating Damaged Myocardium: A Review of Stem-Cell Therapies for Heart Failure

Cells ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 3125
Author(s):  
Dihan Fan ◽  
Hanrong Wu ◽  
Kaichao Pan ◽  
Huashan Peng ◽  
Rongxue Wu
Keyword(s):  
Stem Cells ◽  
Pluripotent Stem Cells ◽  
Cardiac Myocyte ◽  
Cardiac Fibroblasts ◽  
Heart Diseases ◽  
Contributing Factors ◽  
Myocardial Repair ◽  
Cardiovascular Research ◽  
Cell Therapies ◽  
Promising Source

Cardiovascular disease (CVD) is one of the contributing factors to more than one-third of human mortality and the leading cause of death worldwide. The death of cardiac myocyte is a fundamental pathological process in cardiac pathologies caused by various heart diseases, including myocardial infarction. Thus, strategies for replacing fibrotic tissue in the infarcted region with functional myocardium have long been a goal of cardiovascular research. This review begins by briefly discussing a variety of somatic stem- and progenitor-cell populations that were frequently studied in early investigations of regenerative myocardial therapy and then focuses primarily on pluripotent stem cells (PSCs), especially induced-pluripotent stem cells (iPSCs), which have emerged as perhaps the most promising source of cardiomyocytes for both therapeutic applications and drug testing. We also describe attempts to generate cardiomyocytes directly from cardiac fibroblasts (i.e., transdifferentiation), which, if successful, may enable the pool of endogenous cardiac fibroblasts to be used as an in-situ source of cardiomyocytes for myocardial repair.

scholarly journals Function and crystal structure of the dimeric P-loop ATPase CFD1 coordinating an exposed [4Fe-4S] cluster for transfer to apoproteins

2018 ◽  
Vol 115 (39) ◽  
pp. E9085-E9094 ◽  
Author(s):  
Oliver Stehling ◽  
Jae-Hun Jeoung ◽  
Sven A. Freibert ◽  
Viktoria D. Paul ◽  
Sebastian Bänfer ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Iron Homeostasis ◽  
De Novo ◽  
Regulatory Protein ◽  
Protein Translation ◽  
Cluster Assembly ◽  
Cellular Iron ◽  
Chaetomium Thermophilum ◽  
Cellular Iron Homeostasis ◽  
S Proteins

Maturation of iron-sulfur (Fe-S) proteins in eukaryotes requires complex machineries in mitochondria and cytosol. Initially, Fe-S clusters are assembled on dedicated scaffold proteins and then are trafficked to target apoproteins. Within the cytosolic Fe-S protein assembly (CIA) machinery, the conserved P-loop nucleoside triphosphatase Nbp35 performs a scaffold function. In yeast, Nbp35 cooperates with the related Cfd1, which is evolutionary less conserved and is absent in plants. Here, we investigated the potential scaffold function of human CFD1 (NUBP2) in CFD1-depleted HeLa cells by measuring Fe-S enzyme activities or 55Fe incorporation into Fe-S target proteins. We show that CFD1, in complex with NBP35 (NUBP1), performs a crucial role in the maturation of all tested cytosolic and nuclear Fe-S proteins, including essential ones involved in protein translation and DNA maintenance. CFD1 also matures iron regulatory protein 1 and thus is critical for cellular iron homeostasis. To better understand the scaffold function of CFD1-NBP35, we resolved the crystal structure of Chaetomium thermophilum holo-Cfd1 (ctCfd1) at 2.6-Å resolution as a model Cfd1 protein. Importantly, two ctCfd1 monomers coordinate a bridging [4Fe-4S] cluster via two conserved cysteine residues. The surface-exposed topology of the cluster is ideally suited for both de novo assembly and facile transfer to Fe-S apoproteins mediated by other CIA factors. ctCfd1 specifically interacted with ATP, which presumably associates with a pocket near the Cfd1 dimer interface formed by the conserved Walker motif. In contrast, ctNbp35 preferentially bound GTP, implying differential regulation of the two fungal scaffold components during Fe-S cluster assembly and/or release.

scholarly journals Crystal structure and interactions of the Tof1–Csm3 (Timeless–Tipin) fork protection complex

2020 ◽  
Vol 48 (12) ◽  
pp. 6996-7004 ◽  
Author(s):  
Daniel B Grabarczyk
Keyword(s):  
Crystal Structure ◽  
Circadian Rhythm ◽  
Dna Replication ◽  
Binding Site ◽  
Molecular Basis ◽  
Replication Forks ◽  
Repeat Structure ◽  
Chaetomium Thermophilum ◽  
Fork Protection Complex ◽  
Human Orthologue

Abstract The Tof1–Csm3 fork protection complex has a central role in the replisome—it promotes the progression of DNA replication forks and protects them when they stall, while also enabling cohesion establishment and checkpoint responses. Here, I present the crystal structure of the Tof1–Csm3 complex from Chaetomium thermophilum at 3.1 Å resolution. The structure reveals that both proteins together form an extended alpha helical repeat structure, which suggests a mechanical or scaffolding role for the complex. Expanding on this idea, I characterize a DNA interacting region and a cancer-associated Mrc1 binding site. This study provides the molecular basis for understanding the functions of the Tof1–Csm3 complex, its human orthologue the Timeless–Tipin complex and additionally the Drosophila circadian rhythm protein Timeless.

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