Interaction of Lactoferrin with Unsaturated Fatty Acids: In Vitro and In Vivo Study of Human Lactoferrin/Oleic Acid Complex Cytotoxicity.

As shown recently, oleic acid (OA) in complex with lactoferrin (LF) causes the death of cancer cells, but no mechanism(s) of that toxicity have been disclosed. In this study, constitutive parameters of the antitumor effect of LF/OA complex were explored. Complex LF/OA was prepared by titrating recombinant human LF with OA.

[Effect of insertional mutation in the cspA gene encoding the major cold-shock protein on radiation resistance of Escherichia coli].

Plasmid pCspA::Km carrying a cloned mutant allele of the cspA gene for the major Escherichia coli cold-shock protein CspA with an insertion of the kanamycin resistance gene cassette from transposon Tn903 into the core region of the coding sequence causes a 2.3-fold increase in radioresistance of wild-type E. coli cells (cspA+).

[Study of the mechanism of regulating the activity of the ribC gene in Bacillus subtilis].

Sequence analysis of several Bacillus subtilis mutants with increased activity of flavokinase/FAD-synthase and the results of Northern hybridization showed that the TTGCCG-17n-TACATT motif localized to the C-end of the truB gene is a regulatory region that controls the ribC gene at the level of transcription.

[The interaction of the rad201 gene with mei-9 and mei-41 genes in germline cells of Drosophila female].

The effect of Drosophila mutation rad201G1 together with mutations mei-41D5 and mei-9a on the sensitivity of oocytes to induction of dominant lethals (DLs) was studied. To this end, the frequencies of spontaneous and gamma-radiation-induced DLs in consecutive egg batches of females carrying double or single mutations were estimated. Since the effects of the mutations examined are expressed only at the previtellogenetic stages of oogenesis, only newly hatched (0-5-hour-old) females, whose oocytes did not develop farther than stage 7, were irradiated.

[Lysine overproduction mutations in the yeast Saccharomyces cerevisiae and its transfection into industrial Yeast strains ].

Yeast mutants resistant to a toxic lysine analog, thialysine were obtained by a method described in the literature. A strain excreting the maximum amount of lysine (0.45 g/l) was selected from these mutants.

[Effect of a null mutation in the priA gene on radioresistance of Escherichia coli].

According to Kogoma's model of DNA recombination by replication, the PriA protein is involved in the RecBCD pathway of double-strand break (DSB) repair, which is associated with extensive DNA degradation, at the stage of primosome assembly in D-loops (intermediates of strand exchange at the ends of DSB) for the subsequent switch to DSB-induced DNA resynthesis. Comparable data on possible involvement of the PriA protein in the repair of gamma-ray-induced lethal lesions in cells of the wild-type strain of Escherichia coli (strain AB1157) and in two radiation-resistant mutants Gamr445 and Gamr444 were obtained. In all the three strains examined, the null priA2::kan mutation in the structural priA gene was shown to markedly enhance the radiation sensitivity, causing a two- to threefold increase in the slopes of linear dose-survival curves.

[Constitutive inhibition of DNA degradation due to the enzyme RecBCD in the radiation-resistant Escherichia coli K-12 mutant Gam(r)444].

Exonucleolytic degradation of [3]H-labeled DNA was examined in partially purified fractions of lysates obtained from nonirradiated RecBCD enzyme-containing cells of Escherichia coli and in the radiation-resistant mutant Gamr444. The degradative activity was shown to be lowered in these cells to the same extent as in the recBC mutant. The efficiency of plating of the mutant phage T4 2-, DNA of which can be degraded by exonuclease V, was 400-fold higher on the strain Gamr444 than on the wild-type strain AB1157.

[A mutant allele gam18, participating in the RecF repair path in Escherichia coli K-12].

Plasmid pGam18 carrying one of the cloned mutant loci, responsible for enhanced radiation resistance in the strain Escherichia coli Gamr444, was shown to increase resistance to the lethal effect of gamma-rays with a dose modification factor DMF = 2. Enhanced resistance was observed in wild-type cells and in the mutant recBC sbcB, but not recFBC sbcA. This indicates the involvement of a product of the gam18 locus in the RecF pathway of recombinational repair.

[Natural plasmid pSD89 (Cmr) from Salmonella derby K89, which increases the radiation tolerance of Escherichia coli strain K-12].

Several plasmids with molecular mass of 1.3-9 MDa were found in a clinical isolate of Salmonella derby K89 by electrophoresis in agarose gel. One of these plasmids, designated pSD89 (Cmr), was derived from the K89 strain via transformation of the plasmidless recipient S.