Epigenetic and synergistic types of inheritance of the reproductive characters in angiosperms

The author considers three types of hereditary memory (structural, cell and signal), that are realized on different levels of biological organization. These three types of hereditary memory correspond to three types of reproduction: self-replication, cell division and reproduction s. str. Reproductive characters are exemplified with three essential characters in angiosperm plants: dimorphism in population by flower sex; mono-, di- and trystyly of flowers; uni- and biparental mode of seed reproduction. All these characters are considered as "supercharacters" that are controlled by gene ensembles. The correspondence between three types of reproduction and three types of hereditary memory are discussed. The authors reviews also the role of polyploidy (auto- and endoploidy) in the inheritance of reproductive condition. From the information theory point the increase in cell ploidy causes the growth of uncertainty in expression of genes and gene ensembles thus creating new type of variability--epigenetic variation. The change of reproductive strategy in plants is regulated by state of gene and gene ensembles and does not demand structural changes in genome. The reproductive characters of plants in spite its complex structure are inherited in number of generations as a discrete Mendel characters by mono-, di-, ot trihybrid schemas.     

An ACTH-like peptide immunocortin: effect on the activity of cells from the rat adrenal cortex

The effect of immunocortin, an ACTH-like decapeptide VKKPGSSVKV corresponding to the 11-20 sequence of the variable part of the human IgG1 heavy chain on the content of 11-hydroxycorticosteroids (CS) in rat adrenal glands and blood serum in vivo was studied. An intramuscular injection of immunocortin at a dose of 10 microg/kg was found in an hour to induce a twofold decrease in CS content in the adrenal glands and a 1.8-fold increase in the blood serum CS content. At the same time, an immunocortin dose of 100 microg/kg exerted practically no effect on the CS content and its dose of 1000 microg/kg increased the CS content both in adrenal glands and in blood serum by 1.6 and 2.2 times, respectively. Four hours after the injection of any of the three doses of immunocortin, the CS content in adrenal glands did not differ from the control value, and after 24 h the content decreased threefold. Immunocortin was shown to be bound by the ACTH receptors in the membranes of the rat adrenal cortex with a high affinity and specificity (inhibiting the specific binding of 125I-labeled ACTH-(11-24) peptide with Ki of 1.2 nM).     

The influence of local changes in the temperature-dependent conformational mobility of thioredoxins on their thermostability

For the development of a method for the prediction of single point mutations substantially affecting protein thermostability, we studied the effect of the E85R and R82E mutations on the thermostability of thioredoxins from Escherichia coli (Trx) and Bacillus acidocaldarius (BacTrx), respectively. The basic method of investigation was the molecular dynamics simulation of 3D protein models in a particular solvent at different temperatures (300 and 373 K). Some thermolabile regions in Trx, BacTrx, and their mutants were revealed by analyzing the temperature effect on the molecular dynamics of the protein molecule. The effect of single point mutations on the temperature changes of the protein conformation mobility in several thermolabile regions was found. The results of the calculations are in accord with the experimental data indicating that the mutation E85R increases Trx thermostability, whereas the mutation R82E decreases BacTrx thermostability. The thermostability of these proteins was revealed to depend on ionic interactions between the thermolabile regions. The single point mutations change the parameters of these interactions and make them more favorable in the E85R-Trx mutant and less favorable in the R82E-BacTrx mutant. The English version of the paper: Russian Journal of Bioorganic Chemistry, 2004, vol. 30, no. 5; see also http: // www.maik.ru.     

Fluorescent properties of 9-anthracenecarboxamides

A number of new 9-anthracenecarboxamides are synthesized in order to create new fluorescent probes for studying biological systems. The parameters of their fluorescence in organic solvents of various polarities are investigated, and possible mechanisms of internal quenching of fluorescence of these compounds are discussed. One of the compounds, 4-ethoxycarbonylphenylamide of 9-anthracenecarboxylic acid, is shown to be a promising basis for the development of a new fluorescent probe. The English version of the paper: Russian Journal of Bioorganic Chemistry, 2004, vol. 30, no. 6; see also http://www.maik.ru.