Search

A study was conducted to demonstrate that aspen wood undergoing decay by the oxalate producer basidiomycetes Postia placenta contained both 2,5-dimethoxyhydroquinone and laccase activity. The estimated quantify of reactive oxygen species produced by P. placenta laccase in wood which large enough possibly contributed to incipient decay.

The white rot basidiomycete Phanerochaete chrysosporium on cellulose or glucose as the carbon source are grown and monitored to assess the mineralization of a [14.sup.C-labeled] synthetic lignin by ligninolytic competence. The results showed that the cellulose-grown cultures are ligninolytic while the glucose-grown ones are not and the proteomic analysis of partially purified plasma membranes from ligninolytic P. chrysosporium are most likely associated with the outer envelope of the fungus.

Purpose: The aims of this work were: (i) To compare the effects of ionising radiation (IR) on testosterone binding globulin (TeBG) characteristics (serum concentration, cooperativity of androgen binding and affinity for hormone) in divergent mammalian species; (ii) to couple radiation effects with probable TeBG-parameter changes; and (iii) to investigate the prevention of these changes by fungal preparations (in particular – by lipid polyene complexes of Laetiporus sulphureus). Materials and methods: Characteristics of TeBG were investigated in microaliquots of rat and human serum samples using [3H]-5α-dihydrotestosterone ([3H]-DHT) radioligand assays after in vivo exposures to IR (external γ-sources, incorporation of 131I-, 137Cs-radionuclides) at experimental and post-Chernobyl radioecological conditions (doses 0.25–2.2 Gy). Results: Species-specific changes of TeBG parameters were found depending on the type of IR, dose and time after irradiation. Specifically children living in radionuclide contaminated regions (near Chernobyl) were found to have a decrease of positive cooperativity for the TeBG-androgen binding, a drop of TeBG levels, and a decline in hormone affinity. Screening of natural substances (from phanerogams and fungi) detected that lipid polyene complexes of the basidiomycete L. sulphureus allowed recovery of the standard features of TeBG. Conclusions: IR induced a depletion of TeBG from blood simultaneously with species-specific changes of TeBG, which depend on the type of radiation, the dose of radiation (from 0.25 up to 2.2 Gy), and the time after radiation. The Hill coefficient of TeBG (indicating the degree of molecular cooperativity when hormone binding) appeared to be the most radiosensitive marker of the glycoprotein activity because of it is inversely to radiation dose. There are pharmacological possibilities to restore IR-induced “declines” of TeBG's affinity and cooperativity for androgen ligand binding. [ABSTRACT FROM AUTHOR]