[DNA isolated from Streptococcus sp. Thom-1066--the producer of thomicide]. / Izuchenie DNK, vydelennoi iz Streptococcus sp. TOM-1066--produtsenta tomitsida.

Thomicide is a complex preparation including a bacteriocin-like substance. To localize the determinant responsible for synthesis of the bacteriocin-like substance, DNA of the streptococcus producing thomicide was isolated and studied. Equilibrium centrifugation of the total DNA preparation in the gradient of cesium chloride-ethidium bromide yielded DNA of one density. The total DNA preparation was obtained with alkaline and neutral lysis. Restriction analysis of the streptococcal DNA followed by electrophoretic separation in agarose gel in comparison to the DNA standards of lambda phage and plasmid pBR 322 confirmed the absence of the plasmid or any other extrachromosomal DNA. Chromosomal localization of the determinant encoding biosynthesis of the thomicide bacteriocin-like substance was shown.

[Capacity of the polynucleotide phosphorylase-releasing factor to stimulate hybrid cell growth]. / Izuchenie sposobnosti faktora sniatiia polinukleotidfosforilazy stimulirovat' rost kletochnykh gibridov.

The capacity of the partially purified preparation of the polynucleotide phosphorylase releasing factor (PNP-ase RF) from Walker sarcoma for stimulating the growth of hybrid cells and parent myeloma cells has been studied. The preparation of PNP-ase RF at a concentration of 500-50 micrograms/ml has been shown to induce the 3- to 10-fold increase of the number of cells in the culture by the 5th day of incubation without changing the medium.

[Isolation and purification of restriction endonuclease PmiI from Proteus mirabilis 1667]. / Vydelenie i ochistka restriktsionnoi éndonukleasy PmiI iz shtamma Proteus mirabilis 1667.

A new restriction endonuclease Pmi I was detected in Proteus mirabilis 1667. The enzyme hydrolyzes DNA of the phage lambda into 10 electrophoretically separating fragments with molecular weights of 1.3-7.9 mD. With the use of two-stage chromatography on blue sepharose and phosphocellulose it is possible to obtain restriction endonuclease Pmi I free of the admixtures of ballast proteins, nonspecific nucleases and phosphatases.

[Use of different media for growing the producer of the restriction enzyme XBA I]. / Ispol'zovanie razlichnykh sred dlia vyrashchivaniia produtsenta restriktiruiushchego fermenta XBA I.

The possibility of using culture media prepared from local ingredients and intended for growing the producers of restricting enzyme Xba 1 has been demonstrated. The yield of restricting enzyme Xba 1 per g of crude biomass, obtained with the use of peptone-yeast medium prepared from ingredients supplied by Difco Laboratories (USA), has proved to be 4 times greater than that obtained with the use of peptone-yeast medium prepared from local ingredients. At the same time the use of casein-saline medium ensures the yield of the enzyme, similar to that obtained with the use of peptone-yeast medium prepared from ingredients supplied by Difco Laboratories, but with a greater content of nonspecific nucleases.

[Cloning of Bordetella pertussis DNA in an Escherichia coli bacterial cell system]. / Klonirovanie DNK Bordetella pertussis v sisteme bakterial'nykh kletok Escherichia coli.

Hybrid plasmids containing B. pertussis DNA insertions have been constructed with the use of the vector plasmid pBR 322 and the Pst I fragments of B. pertussis DNA. Some properties of the hybrid plasmids are characterized. The possibility of the expression of B. pertussis genes in the protein-synthetizing cell-free system obtained from E. coli has been demonstrated.

[Isolation and purification of restriction endonuclease BpeI from Bordetella pertussis]. / Vydelenie i ochistka restriktsionnoi endonukleazy Bpel iz Bordetella pertussis.

New restriction endonuclease has been isolated from Bordetella pertussis vaccine strain 305 and purified in 1 stage on Sepharose covalently bound with blue dextran. The isolated restrictase has been found capable of breaking down lambda-phag DNA into 7 fragments. According to its specificity, Bpe I is the isoschizomer of Hind III obtained from Haemophilus influenzae strain Rd.

[Purification and properties of a releasing factor of polynucleotide phosphorylase from sarcoma M-1 of rat]. / Ochistka i kharakteristika faktora sniatiia polinukleotidfosforilazy iz sapkomy M-1 krys.

A releasing factor (RF) of polynucleotide phosphorylase (PNPase) isolated and purified from sarcoma M-1 of the rat is a protein with molecular weight of about 8000 and the isoelectric point at 4,0--4,2. The process of PNPase release from the polyribosomes of normal rat liver does not depend on the pH of the medium within the pH range of 7,2--9,0, on temperature within the interval of 0--400 degrees and on incubation time. Inhibition of phosphorolysis by endogenous RNA from normal rat liver polyribosomes requires considerable amounts of RF--approximately 170--800 molecules of RF per molecule of poly(A)+-mRNA. The data obtained suggest that PNPase release from the polyribosomes under the action of RF is not a catalytic process and is caused by competition between RF and PNPase for the binding sites on the mRNA molecule.

[The activity of polynucleotide phosphorylase in polyribosomes of regenerating liver of adult rats, liver of newborn rats and in some reinoculated tumours]. / Aktivnost' polinykleotidfosforilazy v polipibosomakh regeneriruiushchei pecheni krys, novorozhdennykh krysiat i nekotorykh perevivaemykh opukholei

Specific activity and level of polynucleotide phosphorylase (PNPase) in polyribosomes of regenerating liver of adult rats, liver of newborn rats and in malignant tumours of rat (sarcoma M-1 and hepatoma 27) were studied. 24 hours after partial hepatectomy the specific activity and level of PNPase in regenerating liver decreased 3--4 times in the fraction of polyribosomes, bound to the endoplasmic reticulum membranes, and remained at a constantly low level in the fraction of free polyribosomes. The PNPase activity also showed a sharp decrease in the fraction of membrane-bound polyribosomes from newborn rats liver and could not be detected either in free or in bound polyribosomes from sarcoma M-1 or hepatoma 27. The PNPase activity in the fraction of bound polyribosomes increased with a decrease in the rate of liver growth (regenerating liver and newborn rats liver), and reached the level normal for adult animals. Possible mechanisms of regulation of the PNPase activity in animal tissue were studied. It was found that a 2-fold administration of cyclic 3,5'-AMP to intact animals (5 mg per 100 g of body weight) with an interval of 8 hours, corresponding to the interval between two peaks of the increase in cyclic 3,5'-AMP concentration following partial hepatectomy, diminished the PNPase specific activity in polyribosomes by 30%. A factor, presumably of protein origin, which induced a release of PNPase from polyribosomes of normal rat liver but did not affect the activity of the liberated enzyme, was detected in the cell sap of sarcoma M-1 and hepatoma 27.

[Effect of cyclic-3',5'-AMP on rat liver polynucleotide phosphorylase activity]. / Vliianie tsiklo-3',5'-AMF na aktivnost' polinukleotidfosforilazy pecheni krysy

Effect of cAMP on the activity of polynucleotide phosphorylase (PNPase) was studied in polyribosome fraction of rat liver tissue. Intraperitonel administration of cAMP or of theophilline into rats distinctly decreased the PNPase activity in the polyribosome fraction. The cAMP (1-10(-4) M) inhibited the enzymatic activity only by 8% in polyribosome fraction in vitro, as it was estimated by the reaction of phosphorolysis of endogenous RNA and polyA added. Any attempts were proved to be uncucessful to reveal cAMP, ATP-dependent proteinkinase in rat liver, responsible for the decrease in the PNPase activity in the polyribosome fraction. The cAMP inhibited the increase in the PNPase activity, coupled with protein biosynthesis in polyribosomes. Moreover, cAMP caused a decrease in the PNPase activity in reaction of polyA phosphorolysis and did not affect the rate of endogenous RNA phosphorolysis in polyribosome fraction, isolated from postmitochondrial fraction after incubation for 15 min at 30 degrees. The 3',5'-cyclo AMP (2-10(-6)-2-10(-4) M) stimulated incorporation of 14C-leucine into acid-insoluble material, when postmitochondrial fraction was incubated under the same conditions. The data obtained suggest that cAMP either inhibits specifically the PNPase synthesis or represses the coupled with protein biosynthesis formation of active "heavy" type of PNPase from less active "light" type.