Abstract CD spectra of reduced and S‐3‐(trimethylated amino) propylated lysozyme (TMAP lysozyme) have been measured in various solutions containing guanidine hydrochloride or trifluoroethanol (TFE). The CD spectra indicate that there remain residual secondary structures in protein in aqueous solution. The addition of TFE further promotes the formation of secondary structures. In order to examine whether secondary structures are evenly induced over all the polypeptide chain, or locally at particular segments, the limited proteolysis of TMAP lysozyme by trypsin has been performed, and the CD spectra of all the final and intermediate products have been observed in solutions containing TFE. As a result, the fragments vary in a helix‐forming propensity. The CD spectra of peptide fragments T5, T7, T9T10, T12T13, T14T15T16, and T17T18 are not significantly affected by the addition of TFE, where T refers to the nomenclature of R. E. Canfield [(1963), Journal of Biological Chemistry , Vol. 238, pp. 2691–2697]. They are fragments of a helix‐breaking propensity. On the other hand, fragment 12 composed of T1‐T4, and fragments T6T7, T8, and T11, attain secondary structures with the addition of TFE. They are fragments of a helix‐forming propensity. Further, it is found that the fragments of a helix‐forming propensity just correspond to the helical segments in native lysozyme. We examine the interactions between neighboring fragments, which contribute to the stabilization of local structures along the polypeptide chain.
A New cold isostatic press (CIP) was applied for complex shape forming of the green compact of a roller shape with an axis. The new CIP comprises rubber mold having an inside space for filling powder, bendable pressure rubber which the rubber mold is fitted into, a case which the bendable pressure rubber is fitted into, a guide surface for pressure oil between the bendable pressure rubber and the case, and a supply channel of pressure oil which opens on a part of the guide surface which is opposite to an initial region of pressure. By using the new CIP air in powder is squeezed out not to give a bad influence on the course of pressure compacting. Results obtained by the epoch-making method of the new CIP were as follows. (1) The compact of the roller with an axis was formed on the condition that the hardness of the rubber mold was smaller than that of the pressure rubber. (2) The green density of the compact was uniform.
