Identification of the forms of human leukemia using polyclonal antibodies to erythroblast antigen

Using polyclonal antibodies to an interspecies antigen of erythroblasts (Ag-Eb) with a molecular weight 69 000 D this antigen was revealed by immunofluorescence on the cells of the peripheral blood of patients with erythroleukemias and, in several cases, in those with undifferentiated leukemias. The possibility was shown of using these antibodies as a diagnostic tool when studying erythroleukemias and acute undifferentiated leukemias.     

Extracellular proteinases from the phytopathogenic fungus Fusarium culmorum

The growth of Fusarium culmorum fungus on a medium containing thermostable proteins from potato tubers was accompanied by the production of proteinases, exhibiting activity over a broad pH range (from 6.0–10.0). When studied by SDS-PAGE in the presence of β-mercaptoethanol, extracellular proteinases were represented by at least five species with a molecular weight of 30–60 kDa. Inhibitor analysis and studies of enzyme activities with synthetic substrates demonstrated that the culture liquid of Fusarium culmorum contained serine proteinases of various classes. The amount of subtilisin-like proteinases was the highest. A near-complete inhibition of the enzymes was caused by proteinaceous proteinase inhibitors from potato tubers. These data suggest that proteinases of the phytopathogen Fusarium culmorum serve as a metabolic target for natural inhibitors of potato proteinases.     

Trypsin inhibitor from Amaranth (Amaranthys cruentus) leaves

A protein that inhibited the proteolytic activity of trypsin was isolated from amaranth leaves (Amaranthus cruentus) by affinity chromatography on trypsin-Sepharose. The inhibition was noncompetitive (with n-nitroanilide-N-alpha-benzoyl-DL-arginine as substrate) and had a Ki of 11.87 x 10(-7) 7 M. The protein caused a weaker inhibitory effect on chymotrypsin, had no effect on subtilisin, displayed a molecular weight of 8 kDa, and contained no cysteine residues.     

Immunomorphological studies of the antigen associated with squamous cell cancer of the human cervix uteri]

The existence of the antigen associated with human cervical squamous cell cancer in normal and pathologically changed cervical epithelium was studied. Immunocytochemical and immunohistochemical methods were used. It is shown that the levels of the antigen increase significantly as the severity of dysplastic changes in epithelial stratum grows and tumor invasive growth begins. The data obtained indicate that the above tumor-associated marker can be useful in the follow-up for prognosticating a course of cervical cancer and dysplasia.     

Purification of pancreatic kallikrein by the method of affinity chromatography]

Pancreatic Kallikrein was purified by affinity chromatography on BPTI-Sepharose. Immobilized BPTI was prepared via three stages: a) formation of the BPTI--acetylated trypsin complex; b) coupling of the resultant complex with CNBr-activated Sepharose; c) dissociation of the bound complex at pH 2.0 to yield immobilized BPTI and acetylated trypsin. The final product contained 59 X 10(-3) micronmoles insolubilized BPTI/ml Sepharose. Trypsin occurring in commercial Kallikrein preparations was separated by the batch procedure with ovomucoid-Sepharose. This method allows 100-fold purification of commercial Kallikrein.     

Exoproteinases of the Oomycete Phytophthora infestans

When grown in a medium containing heat-stable potato tuber proteins, the oomycete Phytophthora infestans (Mont.) de Bary produces a set of exoproteinases active at neutral and mildly basic pH values. These extracellular proteinases have been shown (by SDS-PAGE in the presence of gelatin) to include at least six components differing in molecular weight. Inhibitory analysis and studies of the effects of the enzymes on various synthetic substrates show that the culture liquid of P. infestans contains mainly serine proteinases (specific for trypsin and subtilisin) and metalloproteinases. Their activity is suppressed by proteinase-inhibiting proteins from potato tubers. It is suggested that exoproteinases of P. infestans may be the metabolic target for natural proteinase inhibitors from potato.     

Trypsin-like proteinases and trypsin inhibitors in fruiting bodies of higher fungi

The activity of trypsin-like proteinases and trypsin inhibitors was measured in fruiting bodies of various species of basidial fungi (Basidiomycetes). Fruiting bodies of all fungi contained these enzymes, with the exceptions of polypore (Coriolus versicolor (Fr.) Karst) and hedgehog fungus (Hericium erinaceus (Fr.) Quel), belonging to the families Polyporaceae and Hericiaceae, respectively, in which the enzyme activities were barely detectable. The activity of trypsin-like proteinases was the highest in fruiting bodies of Boletaceae and Agaricaceae. Fruiting bodies of all fungi contained trypsin inhibitors. The highest activity of trypsin inhibitors was detected in basidiomycetes of the families Boletaceae, Agaricaceae, and Pleurotaceae, including Boletus castanus (Fr.) Karst, orange-cap boletus (Leccinum aurantiacum (Fr.) Sing), and brown-cap boletus (Leccinum melanum (Fr.) Karst).     

Larvae of related Diptera species from thermally contrasting habitats exhibit continuous up-regulation of heat shock proteins and high thermotolerance

A population of Stratiomys japonica, a species belonging to the family Stratiomyidae (Diptera), common name ‘soldier flies’, occurs in a hot volcanic spring, which is apparently among the most inhospitable environments for animals because of chemical and thermal conditions. Larvae of this species, which naturally often experience temperatures more than 40 °C, have constitutively high concentrations of the normally inducible heat-shock protein Hsp70, but very low level of corresponding mRNA. Larvae of three other species of the same family, Stratiomys singularior, Nemotelus bipunctatus and Oxycera pardalina, are confined to different type semi-aquatic habitats with contrasting thermal regime. However, all of them shared the same pattern of Hsp70 expression. Interestingly, heat-shock treatment of S. japonica larvae activates heat-shock factor and significantly induces Hsp70 synthesis, whereas larvae of O. pardalina, a species from constant cold environment, produce significantly less Hsp70 in response to heat shock. Adults of the four species also exhibit lower, but detectable levels of Hsp70 without heat shock. Larvae of all species studied have very high tolerance to temperature stress in comparison with other Diptera species investigated, probably representing an inherent adaptive feature of all Stratiomyidae enabling successful colonization of highly variable and extreme habitats.     

Secretion of proteolytic enzymes by three phytopathogenic microorganisms

Serine proteinases from three phytopathogenic microorganisms that belong to different fungal families and cause diseases in potatoes were studied and characterized. The oomycete Phytophthora infestans (Mont.) de Bary and the fungi Rhizoctonia solani and Fusarium culmorum were shown to secrete serine proteinases. An analysis of the substrate specificity of these enzymes and their sensitivity to synthetic and protein inhibitors allowed us to refer them to trypsin- and subtilisin-like proteinases. The correlation between the trypsin- and subtilisin-like proteinases depended on the composition of the culture medium, particularly on the form of the nitrogen source. A phylogenetic analysis was carried out. In contrast to basidiomycetes R. solani, ascomycetes F. culmorum and oomycetes P. infestans produced a similar set of exoproteinases, although they had more distant phylogenetic positions. This indicated that the secretion of serine proteinases by various phytopathogenic microorganisms also depended on their phylogenetic position. These results allowed us to suggest that exoproteinases from phytopathogenic fungi play a different role in pathogenesis. They may promote the adaptation of fungi if the range of hosts is enlarged. On the other hand, they may play an important role in the survival of microorganisms in hostile environements outside their hosts.