[The effect of the lectin from Sambucus nigra inflorescences on spontaneous and alkylating agent-induced mutagenesis in mammalian somatic cells]. / Vliianie lektina sotsvetii Sambucus nigra na spontannyi i indutisrovannyi alkiliruiushchim agentom mutagenez v somaticheskikh kletkakh mlekopitaiushchikh.

Data on separation of purified galactose-specific lectin as well as its two polypeptide chains from inflorescences of European elder Sambucus nigra are represented. Their molecule quaternary structure after the pattern a2 b2 is suggested. It was shown that purified protein in concentration 2.0 mg/ml had mutagenic activity and might enhance mutagenic effect of alkylating substance MNNG. Thus, preparations of lectin from inflorescences of European elder influenced on spontaneous and induced by the alkylating agent mutagenicity in mammalian somatic cells in vitro.

[DNA-methylases from different strains of Bacillus subtilis and Bacillus natto]. / DNK-metilazy razlichnykh shtammov Bacillus subtilis i Bacillus natto.

DNA-methyltransferase activity has been detected in some of Bacillus subtilis and Bacillus natto strains. Two strains of Bacillus subtilis exhibited DNA-cytosine methyltransferase activity, and the strains of Bacillus natto exhibited DNA-adenine methyltransferase activity. A possible effect of DNA-methyltransferase specificity on transformation efficiency is discussed.

[Comparison of the transforming DNA of Bac. subtilis and Bac. natto for sensitivity to EcoR1 restrictase]. / Sravnenie transformiruiushchikh DNK Bac. subtilis i Bac. natto po chuvstvitel'nosti k restriktraze RcoR1.

Transformation procedures were used to study the residual activity of various genetic markers belonging to both Bac. subtilis and Bac. natto after treating their DNAs with EcoRI endonuclease. It is shown that in case of Bac. natto DNA the residual transforming activity of ade, thy and rib markers is 5,10 times higher in comparison with Bac. subtilis DNA. Bac. natto is suggested to be used as a source of genes in gene engineering.

[Heterologous transformation: search for an explantation of the high effectiveness of Bacillus subtilis transformation achieved by using Bacillus natto DNA]. / Geterologischeskaia transformatsiia: poisk ob''iasneniia povyshennoi éffektivnosti transformatsii kletok Bacillus subtilis, osushchestvliaemoi s pomoshch'iu DNK.

A higher efficiency of B. subtilis cells transformation by B. natto DNA is true for every concentration of DNA and is not due to the helping effect known for streptococci, strain Challis. In competition experiments for DNA uptake unlabelled B. natto and B. subtilis DNAs when added to transforming H3-DNA reduced the radioactivity of the samples by a factor of three and two, respectively. A conclusion is drawn that a higher rate of B. natto DNA penetration to the B. subtilis cells results in a higher efficiency of their transformation.