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Graphical abstract, Highlights • Structural flexibility of the tetanus neurotoxin has been investigated. • Crystal structures of reduced TeNT, isolated HN and HC were determined. • TeNT undergoes domain rotation via its own rotation linker. • The dynamics of the so-called Belt region in solution was investigated. • These structural information that shed light on transmembrane mechanism of TeNT., Although the tetanus neurotoxin (TeNT) delivers its protease domain (LC) across the synaptic vesicle lumen into the cytosol via its receptor binding domain (HC) and translocation domain (HN), the molecular mechanism coordinating this membrane translocation remains unresolved. Here, we report the high-resolution crystal structures of full-length reduced TeNT (rTeNT, 2.3 Å), TeNT isolated HN (TeNT/iHN, 2.3 Å), TeNT isolated HC (TeNT/iHC, 1.5 Å), together with the solution structures of TeNT/iHN and beltless TeNT/iHN (TeNT/blHN). TeNT undergoes significant domains rotation of the HN and LC were demonstrated by structural comparison of rTeNT and non-reduced-TeNT (nrTeNT). A linker loop connects the HN and HC is essential for the self-domain rotation of TeNT. The TeNT-specific C869-C1093 disulfide bond is sensitive to the redox environment and its disruption provides linker loop flexibility, which enables domain arrangement of rTeNT distinct from that of nrTeNT. Furthermore, the mobility of C869 in the linker loop and the sensitivity to redox condition of C1093 were confirmed by crystal structure analysis of TeNT/iHC. On the other hand, the structural flexibility of HN was investigated by crystallographic and solution scattering analyses. It was found that the region (residues 698–769), which follows the translocation region had remarkable change in TeNT/iHN. Besides, the so-called belt region has a high propensity to swing around the upper half of TeNT/iHN at acidic pH. It provides the first overview of the dynamics of the Belt in solution. These newly obtained structural information that shed light on the transmembrane mechanism of TeNT.

本稿の目的は，日本およびドイツ，中でも旧東ドイツ地域に属するザクセン州における二分岐型中等学校制度につい\て，社会システム理論の視座から比較考察を行い，ポスト単線型としての二分岐型中等学校制度の特質を提示することである。考察を進めるにあたっては，ルーマン（Luhmann, N.）のコミュニケーション・メディアに関する議論を参照し，特に教育システムにおけるコミュニケーション・メディアとしての「経歴（＝学歴）」のインフレ／デフレという視点から検討した。考察の結果，以下の結論を得た。日本とザクセン州とで共通しているのは，いずれの二分岐型制度もプレ単線型としての分岐型制度とは異なり，それぞれの学校系統を特定の機能システム領域に特化して接続させる方向とはなっていない点である。ポスト単線型としての二分岐型制度においては，２つの学校種は教育システムにおいて内部分化した別々のシステムを基盤とするのではなく，より自律性を高めた教育システムの同一の地平の上での，「より良い／より劣る」の２値コードによるコミュニケーションの展開を基盤として成立していると考えられ，ここにポスト単線型としての再分岐型化の特徴を見出すことができる。

An analytical method of the elastic and the inelastic lateral buckling of restrained beams is presented using the transfer matrix method. The field transfer matrix is derived under the assumption that each element is in a uniform bending moment and it is presented that the various restraints against the out of plane deformations at the supports and in the spans can be considered in the analysis using the point transfer matrix. The treatments of the boundary conditions and the effects of the locations of loadings are given. Using this method, the numerical examples are presented for simply supported beams and two-span continuous beams.