[Spatial structure of isoleucine pentapeptides Glu-Phe-Leu-Arg-Ile-NH2 and Pro-Phe-Tyr-Arg-Ile-NH2].

The spatial structure of two cardioactive isoleucine pentapeptides Glu-Phe-Leu-Arg-Ile-NH2 (I) and Pro-Phe-Tyr-Arg-Ile-NH2 (II) have been investigated using the theoretical conformational analysis. The low-energy conformations of these molecules were found, the values of dihedral angles of the backbone and side chains of the amino acid residues constituting these peptides were determined, and the energies of intra- and interresidual interactions were estimated. It was revealed that the spatial structure of molecule I can exist as five and that of molecule II as seven stable backbone forms.

[Spatial structure of the cardioactive octapeptide].

The spatial structure of the cardioactive octapeptide Pro1-Gln2-Asp3-Pro4-Phe5-Leu6-Arg7-Ile8-NH2 was investigated using the theoretical conformational analysis. The low-energy conformations of the octapeptide molecule were found, the values of dihedral angles of the backbone and side chains of the amino acid residues constituting the peptide were determined, and the energies of intra-and interresidual interactions were estimated. It was shown that the spatial structure of this molecule represent six stable low-energy forms of the main chain.

[Tertiary structure of myelopeptides. II. Conformational analysis of Phe-Arg-Pro-Arg-Ile-Met-Thr-Pro, Val-Val-Tyr-Pro-Asp, and Val-Asp-Pro-Pro].

Theoretical conformational analysis was used to study the spatial structure and conformational properties of myelopeptides, bone marrow peptide mediators. The low-energy conformations of myelopeptides MP-4 (Phe-Arg-Pro-Arg-Ile-Met-Thr-Pro), MP-5 (Val-Val-Tyr-Pro-Asp), and MP-6 (Val-Asp-Pro-Pro) were found; the values of dihedral angles of backbone and side chains of the amino acid residues were determined; and the energies of intra- and interresidual interactions were estimated.

[Spatial structure of myelopeptides: I. Conformational analysis of MP-1, MP-2, and MP-3].

Theoretical conformational analysis was used to study the spatial structure and conformational properties of myelopeptides, bone-marrow peptide mediators. The low-energy conformations of three hexapeptides MP-1 (Phe-Leu-Gly-Phe-Pro-Thr), MP-2 (Leu-Val-Val-Tyr-Pro-Trp), and MP-3 (Leu-Val-Cys-Tyr-Pro-Gln) were found, the values of dihedral angles of the backbone and side chains of the amino acid residues constituting these peptides were determined, and the energies of intra- and interresidual interactions were estimated.

[Structural organization of 2C-terminal region and its analogs in a subunit of ribonucleotide reductase from herpes virus].

By means of conformational analysis, the spatial structure and conformational potential of the H-Tyr-Ala-Gly-Ala-Val-Val-Asn-Asp-Leu-OH molecule, which corresponds to sequence 329-337 of the subunit 2 C-terminal region of the herpes virus ribonucleotide reductase, were studied. It was shown that its spatial organization can be described by a set of 17 low-energy conformations of the backbone. The "reverse conformational problem" for this molecule was solved to enable the prediction of a series of synthetic analogues matching the set of low-energy, potentially physiologically active conformations.