Early events of folding of β-structure-rich protein

富含β结构的蛋白质折叠的早期事件

• 批准号: 16540373
• 负责人: KIHARA Hiroshi
• 金额: $ 2.3万
• 依托单位: Kansai Medical University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2004
• 资助国家: 日本
• 起止时间: 2004 至 2006
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-16540373/
• 关键词: protein folding; alpha-helical burst; SH3 domain; beta-structure-rich protein; β構造蛋白質; 蛋白質のフォールディング; 2次構造; src SH3; fyn SH3; クライオストップトフロー; 円偏光二色性; X線溶液散乱; フォールディング; β構造; SH3ドメイン蛋白質; フォールディング中間体

Protein folds via definite pathway. The purpose of the folding study is to find its folding pathway. We have developed cryo-stopped-flow apparatus with circular dichrosism, x-ray scattering and fluoresecence as probes. We have investigated various types of proteins. Results with alpha-helical protein show the folding rate of alpha-helix formation is so rapid that we cannot measure the rate of alpha-helix formation. In contrast, proteins, mainly consisting of beta-structure, take alpha-helix-rich intrmeditate at its earliest stage. We have focused the folding of SH3, which takes beta-conformation at its native state.SH3 takes alpha-helix-rich intermediate at its earliest stage of folding. We then investigated other beta-structure-rich proteins, and found the intermediate appeared without exception. We compared the amplitude of the burst with other parameters, and found the burst amplitude has good relationship with the helical fraction calculated by a program, Helix2. The program is mainly based on helix-coil transition theory with experimental data of adjacent residues. This suggest that the initial folding cores are formed by the interaction of short-lived alpha-helices.By the one residue mutation of SH3 (Alanine 45 to Glycine), we found the conformation changed from beta-rich to alpha-rich at pH3. This indicates the conversion of beta to alpha occurs more frequently than expected.

蛋白质通过明确的途径折叠。折叠研究的目的是寻找其折叠途径。我们开发了以圆二色性、X射线散射和荧光为探针的低温停流装置。我们研究了各种类型的蛋白质。 α-螺旋蛋白的结果显示α-螺旋形成的折叠速率非常快，以至于我们无法测量α-螺旋形成的速率。相比之下，主要由β结构组成的蛋白质在最早阶段就采取富含α螺旋的中间结构。我们重点关注SH3的折叠，它在其天然状态下采用β构象。SH3在折叠的最早阶段采用富含α螺旋的中间体。然后我们研究了其他富含β结构的蛋白质，发现中间体无一例外地出现。我们将脉冲串的振幅与其他参数进行了比较，发现脉冲串的振幅与Helix2程序计算的螺旋分数有很好的关系。该程序主要基于螺旋-螺旋转变理论和相邻残基的实验数据。这表明最初的折叠核心是由短寿命的α螺旋相互作用形成的。通过SH3的一个残基突变（丙氨酸45到甘氨酸），我们发现构象在pH3下从富含β变为富含α。这表明从 beta 到 alpha 的转换发生的频率比预期的要高。

项目成果

Transient alpha-helical struture during folding of src SH3 domain at subzero temperatures

零下温度下 src SH3 结构域折叠过程中的瞬态 α 螺旋结构

• 期刊: J. Kansai Medical University in press
• 作者: Zhijie Qin;Sandip Vyas;Anthony L. Fink;Jinsong Li;Hiroshi Kihara
• 通讯作者: Hiroshi Kihara

Transient alpha-helical structure during folding of src SH3 domain at subzero temperatures

零下温度下 src SH3 结构域折叠过程中的瞬态 α 螺旋结构

• 期刊: J. Kansai Medical University (in press)
• 作者: Zhijie Qin;Sandip Vyas;Anthony L. Fink;Jinsong Li;Hiroshi Kihara
• 通讯作者: Hiroshi Kihara

Structure of Escherichia coli uracil DNA glycosylase and its complexes with nonohydrolyzable substrate analogues in solution observed by synchrotron small-angle X-ray scattering

同步加速器小角X射线散射观察溶液中大肠杆菌尿嘧啶DNA糖基化酶及其与不可水解底物类似物的复合物的结构

• 发表时间: 2006
• 期刊: Biofizika 51
• 作者: Timchenko;S.K.;Kubareva;E.A.;Volkov;E.M.;Voronina;O.L.;Lunin;V.G.;Gonchar;D.A.;Degtiarev;S.K.;Timchenko;M.A.;Kihara;H;Kimura;K
• 通讯作者: K

Structure of Escherichia coli uracil DNA glycosylase and its complexes with nonhydrolyzable substrate analogues in solution observed by synchrotron small-angle X-ray scattering

同步加速器小角X射线散射观察溶液中大肠杆菌尿嘧啶DNA糖基化酶及其与不可水解底物类似物的复合物的结构

• 发表时间: 2006
• 期刊: Biofizika 51
• 作者: Timchenko;S.K.;Kubareva;E.A.;Volkov;E.M.;Voronina;O.L.;Lunin;V.G.;Gonchar;D.A.;Degtiarev;S.K.;Timchenko;M.A.;Kihara;H.;Kimura;K.
• 通讯作者: K.

Solvent tuning collapse and helix formation timescales of λ_<6-85>

溶剂调谐塌陷和螺旋形成时间尺度 λ_<6-85>

• 发表时间: 2006
• 期刊: Protein Science 15
• 作者: C.Dumont;Y.Matsumura;S.J.Kim;J.Li;Elena Kondrashkina;H.Kihara;M.Gruebele
• 通讯作者: M.Gruebele