ABSTRACT
A metallocarboxypeptidase produced by Streptomyces bikiniensis 27 strain (VKPM Ac-1783) (CPSb) was purified and characterized. The enzyme cleaves both basic and hydrophobic C-terminal amino acid residues from synthetic peptides, that is, it possesses specificity of mammalian carboxypeptidases A and B. The enzyme also hydrolyzes peptides bearing glutamic acid at the C-end. CPSb exhibits its maximal activity at pH 7.0-7.6 and 55°C. The nucleotide sequence encoding the mature CPSb in S. bikiniensis 27 (VKPM Ac-1783) genome (Accession No. GU362077) was determined. It is shown that the primary structure of the mature enzyme has a moderate degree of identity with orthologs from Streptomyces griseus (79% identity) and Streptomyces avermitilis (85% identity).
Subject(s)
Carboxypeptidases/chemistry , Streptomyces/enzymology , Amino Acid Sequence , Carboxypeptidases/isolation & purification , Carboxypeptidases/metabolism , Hydrogen-Ion Concentration , Hydrolysis , Molecular Sequence Data , Peptides/chemistry , Peptides/metabolism , Streptomyces/metabolism , Streptomyces griseus/enzymology , Streptomyces griseus/metabolism , Substrate Specificity , TemperatureABSTRACT
The strain B-1166 differs from the other strains of Bacillus thuringiensis ssp. finitimus because it has two crystal types with different localization in the sporulating cell, i.e., inside and outside of exosporium membrane. Two dissociants of the strain were obtained containing only one of the crystal types. The initial strain produces at least three various delta-endotoxins (Fin2, Fin3, and Fin5) differing from all other known entomocidal proteins; Fin2 and Fin3 are similar to each other but differ from Fin5. Both crystal types contain the same endotoxins (Fin2, Fin3, and Fin5). In the B-1166 strain the site of crystal deposition is not determined by their protein composition.
Subject(s)
Bacillus thuringiensis/chemistry , Bacterial Proteins/chemistry , Bacterial Toxins/chemistry , Endotoxins/chemistry , Amino Acid Sequence , Bacillus thuringiensis/ultrastructure , Bacillus thuringiensis Toxins , Chromatography, Ion Exchange , Electrophoresis, Polyacrylamide Gel , Hemolysin Proteins , Immunodiffusion , Microscopy, ElectronABSTRACT
P33 protein was isolated from the cell walls of Candida utilis. Homology between P33 and Bgl2p proteins from the cell walls of Saccharomyces cerevisiae was shown. The important role of these proteins in molecular organization of yeast cell walls was demonstrated using trypsin proteolysis and the "gene disruption" method.
Subject(s)
Candida/genetics , Cell Wall/metabolism , Fungal Proteins/genetics , Glucan Endo-1,3-beta-D-Glucosidase/genetics , Saccharomyces cerevisiae Proteins , Saccharomyces cerevisiae/genetics , Candida/metabolism , Cloning, Molecular , Humans , Infant, Newborn , Saccharomyces cerevisiae/metabolism , Sequence HomologySubject(s)
Leukemia, Lymphoid/mortality , Adult , Female , Humans , Male , Middle Aged , Prognosis , Time FactorsABSTRACT
A model of the phenomenon of selectivity of antineoplastic phase-specific preparations in leukemia, based on the assumption that any proliferating cells are equally sensitive to the action of such preparations, is suggested. Therefore, selectivity, the concept and fundamental significance of which were formulated and substantiated by the authors earlier, can be expressed in terms of the proliferative pathways of the normal and leukemic populations, the ratio between which thus plays the deciding role in the selection of the optimum system of therapy. The concept of maximum selectivity, which is a convenient numerical characteristic of a preparation, was introduced. A comparative quantitative analysis was made of a number of antineoplastic preparations (vinblastine, vincristine, amethopterin, arabinosylcytosine, azaserine); it showed that the conclusions of the model do not contradict the experimental data.
