[Left-helical (PPII-PPII) type of globular protein structure: the level of the left helical type of poly-L-proline II in Kunitz trypsin inhibitor is no less than 43%. Experimental Reper spectrum of the extended left helix].

There is established that the protein trypsin inhibitor Kunitz is a globular protein of (PPII-PPII)-type. The content of poly-L-proline helix is not smaller than 43%. It has been shown by CD method that the transition from an extended left-handed helical structure to alpha-helix arises on heating till the denaturation temperatures.

[Conformation of a triple collagen spiral as a function of primary structure].

It has been shown by the method of conformational analysis that conformation of the polypeptide chain of a collagen molecule varies from one type of sequence to another, but in all the sequences the only two types of conformations can be characterized by minimal conformational energy. The collagen molecule as a whole is a combination of the single-bond Rich and Crick model and new double-bonded structure. Rigorous comparison with "thick" conformations obtained by Scheraga and coworkers was undertaken using precise calculations with flexible proline.

[A test for the structure of the left helix of poly-L-proline type II in peptides].

The spectral criterion of a left-handed helix of the poly-L-proline II type was elaborated during the study of a number of synthesized oligopeptides (in a solid state and solution): (Gly-Pro-Pro)1-8, (Gly-Pro)1, (Gly-Pro-Ala)1-4, (Gly-Pro-Gly)1-4, (Gly-Pro-Pro) X (Gly-Pro-Gly)1-2(Gly-Pro-Pro), (Gly-Pro-Pro)n, (Orn3-Gly)n and also rat skin collagen by X-ray diffraction, circular dichroism and infrared spectroscopy methods; the characteristic shape of the left-handed helix CD spectrum was found. The change of spectral characteristics with the change of left-handed helix distortion was established. The linear noncooperative melting process of the left-handed conformation was demonstrated.

[Connectin from muscle cells is a collagen protein].

By X-ray analysis a collagen-like structure was observed in the muscle protein connectin . Hydration of species gives a clearer diffraction pattern, which is characteristic of the collagen-like structures. The functional role of connectin should consist in the fixation of maximum length of muscular cells.