Biomedical subjects

A Z Ponomareva

Publications and source records attributed to A Z Ponomareva.

3 recordsLinked to original sources

PubMed1990

[Effect of mitomycin on the biosynthesis of extracellular endonuclease by Serratia marcescens].

The effect of mitomycin C on extracellular endonuclease activity of Serratia marcescens was studied. It was shown that in a concentration of 0.02-1.0 micrograms/ml, mitomycin C markedly increased biosynthesis of the endonuclease by growing and washed cells, the cell productivity being increased 80-100 times. The highest increase in the cell productivity was observed when mitomycin C was added to the cells at the end of the growth exponential phase. The increase in the activity of the extracellular endonuclease was due to the de novo synthesis of the enzyme since it was inhibited by chloramphenicol.

Chloramphenicol↗

PubMedDate not supplied

[Endonuclease from Proteus mirabilis].

Two isoforms of nuclease displaying DNase and RNase activities were found in the culture liquid and periplasm of Proteus mirabilis. The enzyme was isolated from the periplasm and then purified to a functionally homogeneous state. The nuclease was equally potent in cleaving denatured and native DNAs by the endonuclease mechanism and was designated Pm endonuclease. The endonuclease was shown to be a temperature-dependent enzyme with a pH optimum of 10.4-10.6, requiring the presence of bivalent metal ions and inhibited by citrate and ethylenediaminetetraacetate.

Bacterial Proteins↗

PubMedDate not supplied

[Induction of intracellular endonuclease synthesis in Serratia marcescens by agents suppressing DNA replication].

Endonuclease synthesis in Serratia marcescens was studied in the presence of agents selectively suppressing DNA biosynthesis: nalidixic acid, mitomycin, hydroxyurea and thymine limitation. All the agents suppressing DNA replication induced exocellular endonuclease biosynthesis irrespective of their action mechanism. The greatest inducing effect was exerted when the agents were added to cells in the late exponential phase. Endonuclease biosynthesis was induced 1-2 hours after adding the agent and was inhibited with chloramphenicol. The induction of exocellular endonuclease synthesis in Serratia marcescens by the classical inducing agents of a SOS response seems to be indicative of a Lex A regulated process.

DNA Replication↗