並列タイトル等Osmotic Effects on an Allosteric Protein With a Single Interface
一般注記type:Working Paper
研究成果の概要 (和文) : 両親媒性溶質を用いて,ヘモグロビンの構造的・機能的解剖を行った。ベタインの存在下では,酸素親和性の低下は浸透圧ストレスで解釈ができた。一方,3-(1-Pyrido)-1-propane sulfonateの存在下では,デオキシ状態が安定化されたことによって酸素親和性が低下した。驚いたことに,dimethylbenzylammonium propane sulfonate濃度の増加につれて,Hbのデオキシ状態の酸素親和性が徐々に上昇し,オキシ状態の酸素親和性が低下した。しかし,酸素結合協同性に関しては十分に残された。これらの結果はMWCアロステリックモデルに支持しないということが分かった。
研究成果の概要 (英文) : By using three amphoteric amphipathic kosmotropes, we were able to split hemoglobin into its two minimal allosteric component, dimers of the form alpha1beta1, and study their oxygen binding characteristics. In the presence of betaine, the decrease in oxygen affinity was explained in terms of osmotic stress: oxygen affinity dropped as a result of a stabilization of the deoxy conformation. However, in the presence of 3-(1-Pyrido)-1-propane sulfonate, the oxygen affinity of the deoxy conformation of Hb rather increased and ligation cooperativity decreased. In the presence of dimethylbenzylammonium propane sulfonate, with increasing concentrations of this solute, there was not only an increase in the affinity for the deoxy conformation, but also a decrease in affinity for the oxy conformation. NHowever, cooperativity was not abolished. This trait is not compatible with the classical two-state model, since a change in the oxy conformation is not expected, and dimers are non-cooperative.
一次資料へのリンクURLhttps://hosei.ecats-library.jp//da/repository/00012202/14_kaken_tsuneshige.pdf
連携機関・データベース国立情報学研究所 : 学術機関リポジトリデータベース(IRDB)(機関リポジトリ)