通过深紫外线共振拉曼光谱学揭示的粉样β纤维的交叉β核的结构变化
Ludmila A Popova1, Ravindra Kodali, Ronald Wetzel
1Department of Chemistry University at Albany, SUNY, 1400 Washington Avenue, Albany, New York 12222, USA.
Journal of the American Chemical Society
|April 22, 2010
概括
用深紫外线共振拉曼 (DUVRR) 光谱分析了粉样纤维结构. 研究人员在粉样蛋白-β纤维中发现了明显的并行和反并行β叶形状,与球状蛋白质不同.
科学领域:
- 生物化学 生物化学
- 结构生物学 结构生物学
- 频谱学是一种光谱学方法.
背景情况:
- 粉样纤维素的形成 (纤维化发生) 是神经退行性疾病的核心.
- 详细的分子结构特征对于理解纤维细胞生成至关重要.
- 在纤维素中区分平行和反平行β-sheet结构是关键.
研究的目的:
- 探测和区分粉样纤维中的平行与反平行β片结构.
- 为了描述粉样纤维细胞内形状的特征.
- 评估深紫外共振拉曼光谱 (DUVRR) 对于结构分析的实用性.
主要方法:
- 使用深紫外共振拉曼 (DUVRR) 光谱法与-交换 (HX) 结合.
- 分析的纤维是由全长的粉样ββ (Abeta) 1-40) 和Abeta34-42) 制成的.
- 通过对现有的固态NMR数据进行验证的方法来检测阿贝塔 (Abeta) 的1-40) 纤维.
主要成果:
- 与球状蛋白相比,阿贝塔1-40) 纤维的平行β片表现出不典型的形状.
- 在Abeta(32-42) 纤维中的反平行β表显示出一个共同的球状蛋白质结构.
- 通过DUVRR光谱,在阿贝塔纤维核中有效区分了平行和反平行β片的基本不同构造.
结论:
- 粉样纤维素β-表形状与球状蛋白质中的形状不同.
- 在阿贝塔纤维中的平行和反平行β片具有独特的结构特征.
- DUVRR光谱是一种有价值的工具,用于表征粉样纤维中的β叶结构.
相关概念视频
03:03Amyloid Fibrils
Amyloid fibrils are aggregates of misfolded proteins. Under most circumstances, misfolded proteins are either refolded by chaperone proteins or degraded by the proteasome. However, in the case of a mutation or a disease, these proteins can accumulate to form large clusters and often further assemble to form elongated fibers, called fibrils.
Amyloid deposits were observed as early as 1639 in the liver and the spleen. In 1854, Rudolph Virchow performed iodine staining, normally used to...
Amyloid deposits were observed as early as 1639 in the liver and the spleen. In 1854, Rudolph Virchow performed iodine staining, normally used to...
03:03Amyloid Fibrils
Amyloid fibrils are aggregates of misfolded proteins. Under most circumstances, misfolded proteins are either refolded by chaperone proteins or degraded by the proteasome. However, in the case of a mutation or a disease, these proteins can accumulate to form large clusters and often further assemble to form elongated fibers, called fibrils.
Amyloid deposits were observed as early as 1639 in the liver and the spleen. In 1854, Rudolph Virchow performed iodine staining, normally used to...
Amyloid deposits were observed as early as 1639 in the liver and the spleen. In 1854, Rudolph Virchow performed iodine staining, normally used to...
01:20Raman Spectroscopy: Overview
The underlying principle of Raman spectroscopy is based on the interaction between light and matter, specifically molecules' inelastic scattering of photons. When a monochromatic beam of light, typically from a laser source, interacts with a sample, most scattered light has the same frequency as the incident light. This is known as Rayleigh scattering.
However, a small fraction of the scattered light exhibits a frequency shift due to the exchange of energy between the incident photons and the...
However, a small fraction of the scattered light exhibits a frequency shift due to the exchange of energy between the incident photons and the...
01:26Raman Spectroscopy Instrumentation: Overview
A conventional Raman spectrophotometer includes a laser source, a sample holding system, a wavelength selector, and a detector.
The monochromatic laser source, typically using visible or near-infrared radiation, generates a highly focused beam of light. This light interacts with the molecules of the sample, scattering some of the light. Liquid and gaseous samples are usually tested in ordinary glass capillaries, while solids can be analyzed as powders packed in capillaries or as potassium...
The monochromatic laser source, typically using visible or near-infrared radiation, generates a highly focused beam of light. This light interacts with the molecules of the sample, scattering some of the light. Liquid and gaseous samples are usually tested in ordinary glass capillaries, while solids can be analyzed as powders packed in capillaries or as potassium...
00:52¹H NMR of Conformationally Flexible Molecules: Temporal Resolution
At room temperature, the chair conformer of cyclohexane undergoes rapid ring flipping between two equivalent chair conformers at a rate of approximately 105 times per second. These two chair conformers are in equilibrium. The rapid ring flipping results in the interconversion of the axial proton to an equatorial proton and an equatorial to the axial proton. Such interconversions are too rapid and cannot be detected on the NMR timescale. Hence, the NMR spectrometer cannot distinguish between the...
01:19NMR Spectroscopy Of Amines
In proton NMR spectroscopy, primary amines and secondary amines showcase their N–H protons as a broad signal in the chemical shift range between δ 0.5 and 5 ppm. The exact position in this range depends on several factors, including sample concentration, hydrogen bonding, and the type of solvent used. Since amine protons undergo fast proton exchange in solution, the protons are labile and therefore do not participate in any splitting with adjacent protons. Thus, the observed peak is broad and...