Biomedical subjects

B A Grishkovskiĭ

Publications and source records attributed to B A Grishkovskiĭ.

4 recordsLinked to original sources

PubMedDate not supplied

[Conformational features of beta-lipotropic hormone and its fragments].

Structural features of porcine and bovine beta-lipotropic hormone and fragments of porcine hormone have been studied by the methods of circular dichroism and infra-red sectroscopy and by analysis of amino acid sequence. It has been established that the structure of the hormone includes a set of regular helical forms which varies considerably with the humidity and dielectric constant of the medium. The presence of left-handed helical conformations of the poly-L-proline II type in aqueous medium and moist films and their transformations with the variation of the parameters of the medium has been demonstrated. The role of the extended left-handed helical structures in hormone functions in the blood and intercellular space is discussed.

Animals↗

PubMedDate not supplied

[Spectral studies of beta-melanocyte-stimulating hormone and beta-lipotropic hormone fragment].

Secondary structure of beta-melanocyte-stimulating hormone was studied by circular dichoism and infra-red spectroscopy. Left-helical conformation of poly-L-proline II type which was stabilized by temperature reduction was found in aqueous solution; in 60% ethanole the quota of this structure sharply decreased. The investigation of hormone films at different values of relative humidity (in the course of H--D metabolism) made it possible to discover a twisted beta-form and an elongated helix of poly-L-proline II type. Temperature induced changes of circular dichroism spectra specify the peculiarities of poly-L-proline II conformation in C-end fragment of beta-lipotropic hormone.

Circular Dichroism↗

PubMedDate not supplied

[Formation of a hydrate structure in the collagen-like triple helix upon hydration].

By the IR-spectroscopy method successive stages of hydrate envelope formation of the collagen-like triple-helical structure of the monodisperse synthetic polytripeptide Z-(Gly-Pro-Pro)8-OMe were studied. The multistep-type process is followed by isomorphic transitions of the triple-helical structure and by the increasing of hydrogen bond strength.

Collagen↗

PubMedDate not supplied

[Aggregation of poly-L-proline in aqueous solution].

Infrared spectra were measured for both aqueous (D2O) solution and the solid state of form II poly-L-proline in the amide I region as a function of the temperature. The temperature range includes the region where a precipitation is known to occur. From the analysis of spectra of hydrated films and aqueous solutions at different temperatures one can see that there are some peptide C = O-groups which are bounded with water. From this study it has been concluded that poly-L-proline exists in aggregate form even at temperatures lower that required for precipitation. It is supposed that poly-L-proline forms the aggregates including at least 40--50 polypeptide chains with hexagonal packing. At heating crystallisation of such aggregates occurred and it causes precipitation of poly-L-proline II.

Kinetics↗