[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.