Erratum to: Synthesis and Anticancer Activity of Functionalized Thieno[2,3-d]pyrimidine Compounds and Their Triazinyl and Tetrazinyl Derivatives

Russian Journal of Bioorganic Chemistry - erratum     

RETRACTED ARTICLE: Acaricidal and pathogenic effects of the entomopathogenic fungus Beauveria bassiana on engorged females of the fowl tick,Argas persicus (Argasidae)

Experimental and Applied Acarology - This study examined the acaricidal, histopathological and genotoxic effects of the entomopathogenic fungus Beauveria bassiana on engorged females of the fowl...     

Immunolocalization of androgen and vitamin D receptors in the epididymis of mature ram (Ovis aries)

This study illustrated the immunohistochemical distribution of androgen and vitamin D receptors of epididymis in 20 sexually mature ram (Rahmani breed) with average age ranged from (2^_4) years and average weight ranged from (50^_65kg). Androgen receptor was localized in the cytoplasm of both ciliated and non ciliated cells of efferent ductules, besides the principal cells via the entire epididymal duct. The principal cells of both corpus and proximal cauda epididymis showed the highest immunoreactivity to androgen receptors. Furthermore, vitamin D receptor was localized in the cytoplasm of all epithelium of the efferent ductules besides principal cells of all epididymal regions, however the immunoreaction was significantly higher in the efferent ductules, distal caput and distal cauda epididymis. In conclusion, these results suggest that the function of ram epididymis is regulated by both androgen and Vitamin D.     

Purification and characterization of L-amino acid oxidase from the solid-state grown cultures of Aspergillus oryzae ASH

L-Amino acid oxidase (L-AAO) was purified from the solid state-grown cultures of A. oryzae ASH (JX006239.1) by fractional salting out, followed by ion exchange and gel filtration chromatography, to its molecular homogeneity, displaying 3.38-fold purification in comparison with the crude enzyme. SDS-PAGE revealed the enzyme to be a homo-dimer with ～55-kDa subunits, with approximate molecular weight on native PAGE of 105–110 kDa. Two absorption maxima, at 280 nm and 341 nm, for the apoproteinic and FMN prosthetic group of the enzyme, respectively, were observed, with no detected surface glycosyl residues. The enzyme had maximum activity at pH 7.8–8.0, with ionic structural stability within pH range 7.2–7.6 and pH precipitation point (pI) 4.1–5.0. L-AAO exhibited the highest activity at 55°C, with plausible thermal stability below 40°C. The enzyme had T _1/2 values of 21.2, 8.3, 3.6, 3.1, 2.6 h at 30, 35, 40, 50, 60°C with Tm 61.3°C. Kinetically, A. oryzae L-AAO displayed a broad oxidative activity for tested amino acids as substrates. However, the enzyme had a higher affinity towards basic amino acid L-lysine (K _m 3.3 mM, K _cat 0.04 s^?1) followed by aromatic amino acids L-tyrosine (K _m 5.3 mM, K _cat 0.036 s^?1) and L-phenylalanine (K _m 6.6 mM), with 1ow affinity for the S-amino acid L-methionine (K _m 15.6 mM). The higher specificity of A. oryzae L-AAO to L-lysine as substrate seems to be a unique property comparing to this enzyme from other microbes. The enzyme was significantly inhibited by hydroxylamine and SDS, with slight inhibition by EDTA. The enzyme had a little effect on AST and ALT, with no effect on platelet aggregation and blood hemolysis in vivo with an obvious cytotoxic effect towards HepG2 (IC₅₀ 832.2 μg/mL) and MCF-7 (IC₅₀, 370.6 μg/mL) tumor cells in vitro.     

Molecular cloning,biochemical characterization,and antitumor properties of a novel L-asparaginase from <Emphasis Type="Italic">Synechococcus elongatus</Emphasis> PCC6803

L-asparaginase (EC 3.5.1.1), which catalyzes the deamidation of L-asparagine to L-aspartic acid and ammonia, has been widely used as a key therapeutic tool in the treatment of tumors. The current commercially available L-asparaginases, produced from bacteria, have signs of toxicity and hypersensitivity reactions during the course of tumor therapy. Therefore, searching for L-asparaginases with unique biochemical properties and fewer adverse effects was the objective of this work. In this study, cyanobacterial strain Synechococcus elongatus PCC6803 was found as a novel source of L-asparaginase. The L-asparaginase gene coding sequence (gi:939195038) was cloned and expressed in E. coli BL21(DE3), and the recombinant protein (Se.ASPII) was purified by affinity chromatography. The enzyme has high affinity towards Lasparagine and shows very weak affinity towards L-glutamine. The enzymatic properties of the recombinant enzyme were investigated, and the kinetic parameters (K_m, V_max) were measured. The pH and temperature dependence profiles of the novel enzyme were analyzed. The work was extended to measure the antitumor properties of the novel enzyme against different human tumor cell lines.     

alpha-Tomatine, the major saponin in tomato, induces programmed cell death mediated by reactive oxygen species in the fungal pathogen Fusarium oxysporum

The tomato saponin alpha-tomatine has been proposed to kill sensitive cells by binding to cell membranes followed by leakage of cell components. However, details of the modes of action of the compound on fungal cells are poorly understood. In the present study, mechanisms involved in alpha-tomatine-induced cell death of fungi were examined using a filamentous pathogenic fungus Fusarium oxysporum. alpha-Tomatine-induced cell death of F. oxysporum (TICDF) occurred only under aerobic conditions and was blocked by the mitochondrial F(0)F(1)-ATPase inhibitor oligomycin, the caspase inhibitor D-VAD-fmk, and protein synthesis inhibitor cycloheximide. Fungal cells exposed to alpha-tomatine showed TUNEL-positive nuclei, depolarization of transmembrane potential of mitochondria, and reactive oxygen species (ROS) accumulation. These results suggest that TICDF occurs through a programmed cell death process in which mitochondria play a pivotal role. Pharmacological studies using inhibitors suggest that alpha-tomatine activates phosphotyrosine kinase and monomeric G-protein signaling pathways leading to Ca(2+) elevation and ROS burst in F. oxysporum cells.