Biomedical subjects
Publications and source records attributed to T V Gogitidze.
Conformational energy calculations were carried out for angiotensin II. Its spatial structure can be described by two groups of low-energy conformations. The values of all dihedral angles of the backbone and side chains as well as intra- and inter-residual interaction energies were calculated for all potential physiologically active conformations.
A number of modifications of the amido acids sequence of the peptide hormone angiotensin II leading to the hormone's analogues with restricted conformational properties are considered. The relative conformational energies for all the analogues were evaluated in conformations similar to the low-energy conformations of the native hormone. Presented is the comparative analysis of the spatial structures of the native hormone and its analogues.
Conformational properties of the molecules of angiotensin II and some of its analogs are analysed with regard to the quantitative characteristics of their biological activities. Connections between low-energy conformations of angiotensin II and its biological functions are established. The hormone's spatial structures plausible in terms of interactions with the specific receptors located in smooth muscles and adrenal cortex tissues have been identified.
The method of conformational analysis was applied to the spatial structures of peptide analogues of phytochelatins and some fragments of metallothioneins: (Cys-Gly)3, (Cys-Gly)3Asp, (Cys-Gly)3Glu, (Cys-betaAla)3, (Cys-gammaGlu)3, and (Cys-Gly-Gly)3. All the possible low-energy conformations of the molecules were revealed and the role of intra- and inter-residual interactions in the formation of their spatial structures was determined. A different tendency of the molecules under study for acceptance of conformations favorable for binding bismuth ions was shown. Low-energy structures providing an optimum binding of bismuth ion were shown to be most frequent for (Cys-betaAla)3 peptide. Among the analogues of peptide fragments of the metallothioneins, lacking in natural peptides, low-energy pentapeptide CCXXC fragments (where X = Gln, Asn, Phe, Tyr, and Gly) were revealed. In the alpha-helical conformations of these pentapeptides, the distance between the sulfur atoms corresponds to that in Bi2S3. The English version of the paper: Russian Journal of Bioorganic Chemistry, 2006, vol. 32, no. 3; see also http://www.maik.ru.