Journal ArticleDOI
Purification and characterization of a new L-methioninase from solid cultures of Aspergillus flavipes
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TLDR
The purified L-methioninase from solid cultures of A. flavipes displayed unique biochemical and catalytic properties over the currently applied Pseudomonad enzyme.Abstract:
L-Methioninase was purified to electrophoretic homogeneity from cultures of Aspergillus flavipes using anion-exchange and gel filtration chromatography by 12.1 fold compared to the crude enzyme preparation. The purified enzyme had a molecular mass of 47 kDa under denaturing conditions and an isoelectric point of 5.8 with no structural glycosyl residues. The enzyme had optimum activity at pH 7.8 and pH stability from 6.8–8.0 at 35°C. The enzyme appeared to be catalytically stable below 40°C. The enzyme activity was strongly inhibited by DL-propargylglycine, hydroxylamine, PMSF, 2-mercaptoethanol, Hg+, Cu2+, and Fe2+, with slight inhibition by Triton X-100. A flavipes L-methioninase has a higher catalytic affinity towards L-methionine (Km, 6.5 mM and Kcat, 14.1 S−1) followed by a relative demethiolating activity to L-homo-cysteine (Km, 12 mM and Kcat, 9.3 S−1). The enzyme has two absorption maxima at 280 and 420 nm, typical of other PLP-enzymes. Apo-L-methioninase has the ability to reconstitute its structural catalytic state completely upon addition of 0.15 mM PLP. L-Methioninase has neither an appreciable effect on liver function, platelet aggregation, nor hemolysis of human blood. The purified L-methioninase from solid cultures of A. flavipes displayed unique biochemical and catalytic properties over the currently applied Pseudomonad enzyme.read more
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Extracellular l-Asparaginase from a Protease-Deficient Bacillus aryabhattai ITBHU02: Purification, Biochemical Characterization, and Evaluation of Antineoplastic Activity In Vitro
TL;DR: In vitro cytotoxicity assays with HL60 and MOLT-4 cell lines indicated that the l-asparaginase has significant antineoplastic properties and circular dichroism spectroscopy showed that the enzyme belonged to α + β class of proteins with approximately 74 % α-helices and 12 % β-sheets.
Journal ArticleDOI
Aspergillus flavipes is a novel efficient biocontrol agent of Phytophthora parasitica
TL;DR: In an in vitro bioactivity-driven screen of rhizosphere-inhabiting fungi, Aspergillus flavipes was identified as a strong inhibitor for growth of various species of Phytophthora and its antiphytophthoral activity was mostly reported in the ethyl acetate fraction.
Journal ArticleDOI
Purification, immobilization, and biochemical characterization of l-arginine deiminase from thermophilic Aspergillus fumigatus KJ434941: anticancer activity in vitro.
TL;DR: The present findings explored a novel thermostable, less antigenic ADI from thermophilic A. fumigatus, with further molecular and crystallographic analyses, this enzyme will be a powerful candidate for clinical trials.
Kinetic characterization of methionine γ-lyases from the enteric protozoan parasite Entamoeba histolytica against physiological substrates and trifluoromethionine, a promising lead compound against amoebiasis
TL;DR: In this article, the authors compared the kinetic parameters of the wild-type and mutants, engineered by site-directed mutagenesis, of the two MGL isotypes from En.histolytica (EhMGL1 and EhMGL2) for various potential substrates and TFM.
Journal ArticleDOI
Biochemical characterization of peptidylarginine deiminase-like orthologs from thermotolerant Emericella dentata and Aspergillus nidulans.
Ashraf S.A. El-Sayed,Ahmed A. Shindia,Azza A. AbouZaid,Amany M. Yassin,Gul Shad Ali,Mahmoud Sitohy +5 more
TL;DR: This is the first report exploring the molecular properties of PAD from thermotolerant fungi, to imitate the human temperature, and shows that PADs from E. dentata and A. nidulans had a relatively similar conformational and kinetic properties.
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