[Study of the conformation of neurospecific cardioactive glycoproteins by optical spectroscopy]. / Issledovanie konformatsii neirospetsificheskikh kardioaktivnykh glikoproteinov metodami opticheskoi spektroskopii.

Using selective fluorescence quenching and circular dichroism techniques, the conformation of protein carriers of earlier detected cardiotropic hypothalamic neurohormones was investigated. The experimental results point to essential differences in the structural organization of the above compounds that were designated according to the type of their binding to corresponding hormones as BNH, BNC and BNS. For instance, the circular dichroism spectrum of BNS is typical of proteins that are characterized by a high content of non-ordered structures, a low content of beta-structures and an almost complete absence of alpha-helices. BNC and BNH with nearly the same content of alpha-helical structures are distinguished by the number of "non-ordered glomes" which are more abundant in BNC. These results are in good agreement with the fluorescence quenching data.

[Specific hypothalamic proteins]. / O spetsificheskikh belkakh gipotalamusa.

We had previously shown the presence of four protein fractions in hypothalamus of cattle having a coronarodilatatory effect. In this study we have developed methods for the isolation of these proteins and have studied some of their physicochemical properties, amino acid composition, molecular weight, iso-electric point etc. The results obtained have shown that the methods used enable the isolation of quite pure coronaroactive proteins, the content of which in the hypothalamus is equal to 12 mg/kg of fresh tissue. A study of the amino acid composition of these proteins has shown that they are not of the same type. They also differ in molecular weight, in their electrophoretic properties on 7.5% polyacrylamide gel and their iso-electric points. The possibility of a dual function of these proteins as carriers and precursors of corresponding neurohormones is discussed.