Properties of two endoglucanases from a mutant strain Trichoderma sp. M7

Two endoglucanases (1,4--d-glucan-4-glucanohydrolase, EC 3.2.1.4) were purified to electrophoretic homogeneity from the culture filtrate of a mutant strain Trichoderma sp. M₇. The purified endoglucanases had Mr of 57.4 and 55 kDa, and estimated pI values of 4.1 and 3.95/3.75, respectively. Optimal activity for the first cellulase was at pH 4.5 and 50 °C, and at pH 5.5 and 60 °C for the other. Carbodiimide inactivated the one of the purified endoglucanases, while the other was inhibited by iodoacetamide, indicating the involvement of carboxylic or thiol groups in the catalysis. N-Bromsuccinimide strongly inhibited both endoglucanases, suggesting that tryptophan residues are essential for the activity and binding to the substrate.     

Mercury-resistant bacteria from permafrost sediments and prospects for their use in comparative studies of mercury resistance determinants

Mercury-resistant bacteria were isolated from permafrost sediments of Kolyma lowland and Canada existing over five thousand to two million years. Their content was shown to vary within the range 0.001-2.9% and to depend on the amount of mercury in sampling sites (coefficient of correlation 0.75). A collection of mercury-resistant bacterial strains was created. In this collection, various representatives of both Gram-positive bacteria (Bacillus, Exiguobacterium, Micrococcus, Arthrobacter) and Gram-negative bacteria (Pseudomonas, Acinetobacter, Plesiomonas, Myxobacteriales) were identified. Most resistant bacteria were found to contain determinants homologous to mer-operons of contemporary bacteria. The isolated strains of paleobacteria are proposed to be used for a comparative structural study of contemporary and ancient plasmids and transposons carrying mercury resistance determinants.     

Effect of impulse extrabroad-band electromagnetic radiation on electroencephalogram and sleep in laboratory animals

1-hour exposure to ultra-short impulse low-frequency (6 Hz) superbroad band electromagnetic radiation altered cortical EEG in rats just after the exposure and increased the paradoxical sleep in rabbits within 16-22 hours following the radiation.     

Comparative study of the effect of alpha-tocopherol, its synthetic metabolite and ionol on dexamethasone-induced apoptosis in rat thymocytes

alpha-Tocopherol was found to decrease the level of rat thymocytes DNA fragmentation and to increase the viability of these cells under apoptosis induction by dexamethazone. So the antiapoptotic role of this vitamin is suggested. In contrast to alpha-tocopherol synthetic antioxidant ionol and alpha-tocopherylacetate, contained only 6 carbon atoms in its isoprenoid side chain caused the cell death from necrosis. This process preceded the apoptosis stimulated by dexamethazone.     

alpha-Tocopherol increases phosphorylation of rat nuclear proteins,catalyzed by protein kinase C

alpha-Tocopherol added in vivo increased protein kinase C--dependent phosphorylation of rat liver nuclei proteins. Such effect of tocopherol was found also after the addition of sphingosine known as natural inhibitor of protein kinase C to incubation medium. The stimulation of phosphorilation was observed also after the addition of alpha-tocopherol to the Triton X-100 solubilized nuclear fraction which contained protein kinase C and tocopherol-binding proteins.     

Immunotherapy in the complex treatment of patients with atopic dermatitis with sensitization to house dust mites

Ninety-nine patients aged 16-52 years with disseminated atopic dermatitis at the remission were examined and treated. The patients were divided into 3 groups according to the method of therapy. Group 1 (28 patients aged 17-52 years, found to be sensitive to Dermatophagoides pteronyssinus and D. farinae) received, in addition to standard treatment, immunotherapy (oral hyposensitization with mite allergens) in combination with ointment containing retinopalmitate and methyluracil. Group 2 (39 patients aged 17-40 years) received standard treatment combined with the administration of placebo. Group 3 (32 patients aged 16-27 years) received only standard therapy. Groups 2 and 3 were used for comparison. The results of treatment were evaluated according to changes in the immune status of the patients and a complex of clinical characteristics. Essential improvement in clinical characteristics and the normalization of immunological parameters were registered in group 1, which proved that immunotherapy was effective and safe.     

beta-Glucosidase of leaves and roots of the common beet Beta vulgaris

beta-Glucosidases detected in the leaves and roots of common beet, Beta vulgaris, have been demonstrated to catalyze hydrolysis of native betacyanins. A method is described for the isolation and purification of beta-glucosidase from the roots, which involves ammonium sulfate precipitation, DEAE-cellulose chromatography, and Sephadex gel filtration. Maximum activity of the enzyme is detected at 50 degrees C and pH 8.0; it retains stability within the pH range from 5.1 to 9.2. In the leaves, beta-glucosidase is chloroplast membrane-associated; solubilization of the membranes results in the enzyme inactivation.