Molten Globule State of Proteins-Conformation, Stability, and Its Physiological Role

蛋白质的熔球状态——构象、稳定性及其生理作用

• 批准号: 05044131
• 负责人: GOTO Yuji
• 金额: $ 2.56万
• 依托单位: Osaka University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for international Scientific Research
• 财政年份: 1993
• 资助国家: 日本
• 起止时间: 1993 至 1994
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-05044131/
• 关键词: Protein; Electrostatic interaction; Hydrophobic interaction; Solution X-ray scattering; Mass spectrometry; Molten globule state; Molecular chaperon; Protein folding; タンパク質; マススペクトル; 熱ショック蛋白質; タンパク質の構造形成

The molten globule, state, a compact denatured state with significant secondary structure but a largely disordered tertiary structure, has been proposed to be a major intermediate state in protein folding and its participation in various in vivo processes has been suggested. However, much remains unknown-particularly the mechanism of conformational stability and its physiological role. We carried out the International Scientific Research Program in order to clarify these problems and obtained the following results.1)Conformation and stability of the molten globule state Structural characteristics of various conformational state of apomyoglobin were studied by solution X-ray scattering. The results show that the molten globule state is expanded from the native state and that it contains a core comprising a cluster of helices and flaring tails. Role of hydrophobic and electrostatic interactions in stabilizing the molten globule state of apomyogobin and cytochrome c was studied by calorim … More etry and circular dichroism. It was shown that the stability of the molten globule state is critically determined by a balance of charge repulsive forces and hydrophobic forces. By comparing the various conformational states, we constructed a folding profile, which shows that the protein becomes more compact with formation of the secondary structure. The profiles are consistent with the prediction on the basis of the statistical mechanical theory.2.Nature of substrate proteins recognized by molecular chaperons Mechanism of interaction of GroEL and substrate proteins was studied. We found that GroEL recognizes the flexible and exposed hydrophobic clusters of the substrate proteins. On the other hand, DanK was found to recognize more disordered conformational states.3.Analysis of the molten globule state by mass spectrometryH/D exchange reaction of the molten globule state was analyzed by electrospray mass spectrometry. It was indicated that mass spectrometry is useful to characterize the structural flexibility of the molten globule state. Less

熔融球状态是一种紧密的变性状态，具有重要的二级结构，但三级结构很大程度上是无序的，已被认为是蛋白质折叠的主要中间状态，并已被认为参与了各种体内过程。然而，仍有许多未知的，特别是构象稳定性的机制和它的生理作用。本课题组开展了国际科学研究计划，主要研究结果如下：1）熔融球态的构象和稳定性用溶液X射线散射研究了脱辅基肌红蛋白不同构象状态的结构特征。结果表明，熔融球状态是从天然状态扩展的，并且它包含一个由螺旋簇和张开的尾部组成的核心。用量热法研究了疏水和静电相互作用对脱钙肌球蛋白和细胞色素c熔融球稳定性的影响。 ...更多信息 二色性和圆二色性。结果表明，熔融球状态的稳定性是由电荷排斥力和疏水力的平衡决定的。通过比较各种构象状态，我们构建了一个折叠的轮廓，这表明蛋白质变得更加紧凑的二级结构的形成。分子伴侣识别底物蛋白的性质研究了GroEL与底物蛋白的相互作用机理。我们发现GroEL识别底物蛋白的柔性和暴露的疏水簇。另一方面，发现DanK识别更多的无序构象状态。3.熔融球态的质谱分析熔融球态的H/D交换反应用电喷雾质谱分析。结果表明，质谱是有用的表征熔融球状态的结构灵活性。少

项目成果

Kataoka,M.: "Structural Characterization of the Molten Globule and Native States of Apomyoglobin by X-Ray Scattering." J.Mol.Biol.(in press). (1995)

Kataoka,M.：“通过 X 射线散射对熔球和脱肌红蛋白天然状态进行结构表征。”

Hagihara, Y.: "Comparison of the Conformational Stability of the Molten Globule and Native States of Horse Cytochrome c." J.Mol.Biol. 237. 336-348 (1994)

Hagihara, Y.：“熔球构象稳定性与马细胞色素 c 的原生状态的比较。”

De Young, L.R.: "Aggregation and Denaturation of Apomyoglobin in Aqueous Urea Solutions." Biochemistry. 32. 3877-3886 (1993)

De Young，L.R.：“尿素水溶液中脱肌红蛋白的聚集和变性。”

Hoshino,M.: "Perchlorate-Induced Formation of the a-Helical Structure of Mastoparan." J.Biochem.116. 910-915 (1994)

Hoshino,M.：“高氯酸盐诱导 Mastoparan α-螺旋结构的形成”。

Hamada, D.: "Salt-Induced Formation of the Molten Globule State of Cytochrome c Studied by Isothermal Titration Calormetry." Proc.Natl.Acad.Sci.U.S.A.91. 10325-10329 (1994)

Hamada, D.：“通过等温滴定量热法研究盐诱导的细胞色素 c 熔球态的形成。”