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Biomedical subjects

E E Khavkin

Publications and source records attributed to E E Khavkin.

6 recordsLinked to original sources
PubMed1978

[Model for auxin receptor].

Literary data on correlation between the structure and auxin activity of aryl-, arylalkan- and aryloxyalkancarboxylic acids and those of 3-indolylacetic acid are reviewed. The structure of auxins is compared to that of their inactive structural analogs in terms of a literary hypothesis on the bifunctional binding of auxins to the receptor, which allowed to construct a model for the structure of the auxin receptor (site responsible for intrinsic binding of auxins). The geometric parameters of this receptor site and specific arrangement of specific auxin binding sites have been proposed. It is demonstrated that during auxin absorption on the receptor the conformation of the latter is changed, which may be accounted for as a primary functional effect of auxins on the receptor.

Carboxylic Acids↗
PubMed1975

Formation of the enzymatic apparatus of respiration in growing cells. Communication II. Reorganization of the respiratory cycle of mitochondria in the corn root tip.

The content of cytochromes a,b and c, the activity of marker enzymes of the matrix and inner membrane of the mitochondria: glutamate dehydrogenase and cytochrome oxidase, as well as the rate of absorption of O2 by root segments in the presence of respiratory substrates, oxygen, inhibitors of respiration, and dinitrophenol, were determined. The intensification of cell respiration in the phase of elongation is determined not so much by new formation of cytochrome components of the respiratory cycle (during this period there is an accumulation only of cytochrome c) as by reorganization of the respiratory cycle (primarily its portion NADH - cytochrome b) and synthesis of enzymes of the matrix.

Cytochromes↗
PubMed1974

[Formation of the respiratory enzyme apparatus in plant cells. III. Antigenic spectra of mitochondria in the root tip of corn].

By means of one- and two-dimensional (cross) immunoelectrophoresis, immunoelectro-diffusion and radial immunodiffusion, about 20 antigens were detected in mitochondria of meristem, zone of elongation and mature cells, among which some were identified by zymographic methods. The differentiation of root cells is not accompanied by qualitative changes in antigenic spectra of mitochondria and changes in the ratio of antigens (including glutamate and malate dehydrogenases) suggest that mature mitochondria develop from preexisting ones by gradual quantitative changes which are due to different rate of synthesis of constituent proteins.

Antigens↗
PubMedDate not supplied

[Orthologs of arabidopsis CLAVATA 1 gene in cultivated Brassicaceae plants].

In arabidopsis (Arabidopsis thaliana), the CLAVATA1 (CLV1) gene is involved in maintaining the balance between the stem cells in the central zone of the stem apical meristem and the determined cells at its periphery. However, CLV1 has not been previously characterized in other Brassicaceae. Using the direct amplification of genomic DNA, we obtained a full-length CLV1 ortholog from canola plants (Brassica napus), and also three CLV1 fragments from rape (B. rapa), canola (B. napus), and false flax (Camelina sativa), which corresponded to the transmembrane domain and a part of the kinase domain of the CLAVATA1 protein. The nucleotide and deduced amino acid sequences of the full-size CLV1 ortholog from B. napus were similar by 81 and 87% to the prototype gene from arabidopsis; in the case of shorter gene fragments, the similarity was as high as 91-93 and 98%, respectively. By their primary structure, the CLV1 genes in the Brassicaceae considerably differ from its putative structural homologs beyond this family.

Amino Acid Sequence↗