Monofunctional catalase P of Paracoccidioides brasiliensis: identification, characterization, molecular cloning and expression analysis

Within the context of studies on genes from Paracoccidioides brasiliensis (Pb) potentially associated with fungus-host interaction, we isolated a 61 kDa protein, pI 6.2, that was reactive with sera of patients with paracoccidioidomycosis. This protein was identified as a peroxisomal catalase. A complete cDNA encoding this catalase was isolated from a Pb cDNA library and was designated PbcatP. The cDNA contained a 1509 bp ORF containing 502 amino acids, whose molecular mass was 57 kDa, with a pI of 6.5. The translated protein PbCATP revealed canonical motifs of monofunctional typical small subunit catalases and the peroxisome-PTS-1-targeting signal. The deduced and the native PbCATP demonstrated amino acid sequence homology to known monofunctional catalases and was most closely related to catalases from other fungi. The protein and mRNA were diminished in the mycelial saprobic phase compared to the yeast phase of infection. Protein synthesis and mRNA levels increased during the transition from mycelium to yeast. In addition, the catalase protein was induced when cells were exposed to hydrogen peroxide. The identification and characterization of the PbCATP and cloning and characterization of the cDNA are essential steps for investigating the role of catalase as a defence of P. brasiliensis against oxygen-dependent killing mechanisms. These results suggest that this protein exerts an influence in the virulence of P. brasiliensis.     

Sugar‐Based Arylsulfonamide Carboxylates as Selective and Water‐Soluble Matrix Metalloproteinase‐12 Inhibitors

Matrix metalloproteinase‐12 (MMP‐12) can be considered an attractive target to study selective inhibitors useful in the development of new therapies for lung and cardiovascular diseases. In this study, a new series of arylsulfonamide carboxylates, with increased hydrophilicity resulting from conjugation with a β‐N‐acetyl‐d ‐glucosamine moiety, were designed and synthesized as MMP‐12 selective inhibitors. Their inhibitory activity was evaluated on human MMPs by using the fluorimetric assay, and a crystallographic analysis was performed to characterize their binding mode. Among these glycoconjugates, a nanomolar MMP‐12 inhibitor with improved water solubility, compound 3 [(R)‐2‐(N‐(2‐(3‐(2‐acetamido‐2‐deoxy‐β‐d ‐glucopyranosyl)thioureido)ethyl)biphenyl‐4‐ylsulfonamido)‐3‐methylbutanoic acid], was identified.     

Low-Temperature Bainite: A Thermal Stability Study

The thermal stability of nanobainitic structures obtained by heat treating two different high-carbon high-silicon steels at temperatures between 200 °C and 600 °C has been investigated by means of three complementary techniques, i.e., field emission gun-scanning electron microscopy, X-ray diffraction, and high-resolution dilatometry. Three main stages have been established, each of them characterized by a distinctive microstructure. Furthermore, the nanocrystalline structure generated by the bainite reaction confers the steel with an extraordinary tempering resistance.     

Microbiological quality of fresh fruit and vegetable products in Catalonia (Spain) using normalised plate‐counting methods and real time polymerase chain reaction (QPCR)

BACKGROUND: Commercially available fruits and raw and ready‐to‐eat vegetables (n = 445) were examined for aerobic, coliform, and yeast and mould counts using normalised methods. Listeria spp., Listeria monocytogenes and Salmonella spp. were detected by real time polymerase chain reaction (QPCR) after enrichment. RESULTS: Aerobic plate counts ranged from < 10 to > 10⁹ colony‐forming units (CFU) g^?1, with the lowest and highest counts recorded for fruits and sprouts respectively. The highest incidence level of coliforms was found in ready‐to‐eat vegetables, with up to 65.7% of samples containing from 5 to 9 log₁₀CFU g^?1. Yeasts and moulds showed their highest incidence level between 5 and 6 log₁₀ CFU g^?1, with an overall range from < 2 to 9 log₁₀ CFU g^?1. Salmonella spp., Listeria spp. and L. monocytogenes were detected in 0.67, 2.7 and 0.9% respectively of the total samples examined. CONCLUSION: The samples analysed can be gathered into two main groups, one showing low microbial counts (fruits) and a second group (raw whole leaves and roots and packed ready‐to‐eat vegetables) with higher microbial contamination. Although incidence levels of pathogenic bacteria reported here are in the lower range of those reported elsewhere, positive detections highlight the importance of good hygienic measures throughout the whole food chain. Copyright © 2007 Society of Chemical Industry     

Stability of fusaproliferin,a mycotoxin from Fusarium spp

Fusaproliferin (FP) is a mycotoxin produced by some phytopathogenic Fusarium spp which frequently occur on several agriculturally important plants. We measured FP decomposition in dry or wet contaminated wheat samples incubated at various temperatures (80, 120, 180 and 240 °C) for various times (15, 20, 45 and 60 minutes). Water increased FP decomposition at 80, 120 and 180 °C, but a complete destruction of FP occurred at 240 °C only under dry conditions. Treatment of samples with a saturated solution of dichloroisocyanuric acid reduced FP contamination, while physical treatments such as UV irradiation and sonication did not. © 1999 Society of Chemical Industry     

MicroRNA-Mediated Regulation of the Virus Cycle and Pathogenesis in the SARS-CoV-2 Disease

In the last few years, microRNA-mediated regulation has been shown to be important in viral infections. In fact, viral microRNAs can alter cell physiology and act on the immune system; moreover, cellular microRNAs can regulate the virus cycle, influencing positively or negatively viral replication. Accordingly, microRNAs can represent diagnostic and prognostic biomarkers of infectious processes and a promising approach for designing targeted therapies. In the past 18 months, the COVID-19 infection from SARS-CoV-2 has engaged many researchers in the search for diagnostic and prognostic markers and the development of therapies. Although some research suggests that the SARS-CoV-2 genome can produce microRNAs and that host microRNAs may be involved in the cellular response to the virus, to date, not enough evidence has been provided. In this paper, using a focused bioinformatic approach exploring the SARS-CoV-2 genome, we propose that SARS-CoV-2 is able to produce microRNAs sharing a strong sequence homology with the human ones and also that human microRNAs may target viral RNA regulating the virus life cycle inside human cells. Interestingly, all viral miRNA sequences and some human miRNA target sites are conserved in more recent SARS-CoV-2 variants of concern (VOCs). Even if experimental evidence will be needed, in silico analysis represents a valuable source of information useful to understand the sophisticated molecular mechanisms of disease and to sustain biomedical applications.     

Oxidative transformation of aqueous phenolic mixtures by birnessite-mediated catalysis

The catalytic efficiency of birnessite in the removal of catechol, hydroxytyrosol, methylcatechol and m-tyrosol, four phenols commonly present in polluted wastewaters, was studied in mono-substrate solutions or in mixtures of two, three, and four substrates. In single phenolic solutions the transformation order of phenols was catechol>hydroxytyrosol>methylcatechol>m-tyrosol. With phenolic mixtures different responses were observed and the amount of each phenol transformed and the crossing effects among the various phenols depended on the type and number of phenols present in the mixture. In particular, general inhibitory effects were observed for hydroxytyrosol and m-tyrosol that were transformed less when present in combination with the other phenols. By contrast the effects by the presence of more than one phenol were basically annulled for catechol and methylcatechol at 24 h incubation in all the mixtures. A simultaneous, but often no stoichiometric, release of soluble Mn2+ in the reaction mixtures occurred. The multi-substrate systems were designed to mimic birnessite-mediated oxidative processes that could occur under field conditions. Therefore they could be of great interest to environmental and soil science. The use of birnessite as a potential tool for an effective detoxification and recovery of phenol-polluted systems could be also envisaged.