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V F Levchenko

Publications and source records attributed to V F Levchenko.

7 recordsLinked to original sources
PubMed1987

[Block principle of organization and polyfunctional nature of regulatory peptides].

Study on the primary structure of more than 100 regulatory peptides was carried out with the view of determining their structural similarity. Practically all regulatory peptides appeared to be related to each other. One regulatory peptide can bear similarity to several regulatory peptides (RPs) which is realized by different fragments. The structural similarity of RPs was in some cases unexpected, e. g., somatocrinin-thymosin, secretin-endorphin, etc. Gastro-intestinal peptides were related to most RPs. It seems likely that these peptides are the most ancient ones among RPs.

Amino Acid Sequence↗
PubMedDate not supplied

[The similarity of the primary structure and homology of rhodopsin, beta-adrenoreceptor and muscarinic cholinoceptor].

Computer analysis has been made of the primary structure of 6 different types of receptor proteins: rhodopsin, adrenoreceptor, muscarinic acetylcholine receptor, insulin receptor, nicotinic cholinoreceptor, and bacteriorhodopsin. The aim of the present investigation was to elucidate, at least partially, to what extent insignificant similarity in the primary structure of rhodopsin, muscarinic cholinoreceptor and adrenoreceptor is due to divergent, but not convergent, evolution. Nicotinic cholinoreceptor, bacteriorhodopsin and insulin receptor were chosen for comparison with rhodopsin, adrenoreceptor and muscarinic cholinoreceptor since each of these proteins exhibits this or that structural or functional property which is common for rhodopsin, adrenoreceptor or muscarinic cholinoreceptor; on the other hand, nicotinic cholinoreceptor, bacteriorhodopsin and insulin receptor differ from other receptor proteins by their molecular mechanisms. Comparison of the primary structure of rhodopsin, adrenoreceptor and muscarinic cholinoreceptor on the one hand, and insulin receptor, nicotinic cholinoreceptor and bacteriorhodopsin on the other indicates that only the former exhibit similar primary structure, whereas insulin receptor, nicotinic cholinoreceptor and bacteriorhodopsin show no similarity neither in their primary structure, nor in the primary structure of rhodopsin and other receptor proteins which are similar to the latter with respect to their mode of action. The data obtained indicate that similarity in the primary structure between rhodopsin, muscarinic cholinoreceptor and adrenoreceptor is a consequence of divergent, not convergent, evolution; in other words, these receptor proteins are homologous.

Amino Acid Sequence↗
PubMedDate not supplied

[Fast comparison of groups of sequences using computers].

The library of programs for search of identical fragments in groups of amino acid (nucleotide) sequences is described. In order to find the fragments a table of short-key words is created, after that longer coinciding sections are discovered.

Algorithms↗
PubMedDate not supplied

[Homologous sequences in proteins with different functions].

Data on the primary structure of approximately 250 proteins and regulatory peptides are presented. It was shown that functionally different proteins contain homologous sequencies. Growth hormone molecule contains homologous sequencies to several proteins. On the whole, polypeptide hormones more frequently, as compared to other proteins, contained sequencies, which are homologous to fragments of proteins with various functions. Evolutionary aspects of multiple relations between proteins are discussed.

Algorithms↗
PubMedDate not supplied

[Simulation of the macro-evolutionary process on computers].

The discussed model is designed for investigation of peculiarities and dynamics of the growth of evolutionary trees. The model is realized in FORTRAN, properties and principles of interaction of populations being the basis of this model. The results obtained reveal an extreme dependence of the pattern of evolutionary process from the parameters of competition, as well as the fact that evolutionary trees plotted with incomplete number of characters may be entirely different from real ones. It is concluded that many of the known evolutionary phenomena may be sufficiently described by a quantitative model based on the Darwinian principles.

Animals↗