Membrane Structure Analysis by Enhanced Raman Scattering

通过增强拉曼散射进行膜结构分析

• 批准号: 1709084
• 负责人: Jason Hafner
• 金额: $ 33万
• 依托单位: William Marsh Rice University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-07-01 至 2023-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1709084&HistoricalAwards=false
• 关键词: Membrane; Structure; Analysis; Enhanced; Raman

With support from the Chemical Measurement and Imaging Program in the Division of Chemistry, Professor Hafner at Rice develops a new way to measure the structure of biomolecules in the membranes that surround cells. In biology, a biomolecule's structure drives its function, so measuring structures is an important step in understanding life at the molecular scale. Molecules that are components of membranes are not soluble in water so it is a challenging task to solve their structures. Hafner and his group attach these molecules to gold nanoparticles and analyze light that is scattered from them. The nanoparticles focus light to the molecular scale. By monitoring how light scattered, a molecular structure can be determined. This new methodology will be applied to open questions in understanding the function of membranes in biology, as well as helping to understand the effects of molecular probes and drugs widely used in chemical and biological research. Professor Hafner also works on developing course materials on three fundamental scientific concepts behind this research: light waves, light scattering, and molecular vibrations. The developed materials are to be used in the high school teacher professional development programs offered by Rice University where most teachers are coming from Houston Independent School District (HISD).The researcher team develops a new method for biomembrane molecular structure analysis that they have recently concept-proofed. Specifically, lipid membranes is applied to the surface of gold nanorods in solution, and their surface enhanced Raman scattering (SERS) is recorded. The electromagnetic near field of the gold nanorods (responsible for enhancement) and the Raman scattering tensors of the molecules of interest are calculated by the finite element method (FEM) and time dependent density functional theory (TDDFT), respectively. Unenhanced Raman spectra in the absence of gold nanorods are also recorded. Due to the alignment and rapid decay of the near field enhancement, these experimental and theoretical results are then combined through a ratiometric analysis to yield the position and orientation of molecular constituents responsible for specific vibrations. The researchers have recently demonstrated this by measuring the position and orientation of tryptophan in dioleoylphosphatidylcholine lipid membranes. The specific research objectives include: (1) Vibrational markers will be established to further analyze lipid membrane structure as well as the variety of lipids that can be included; (2) The effect of nanorod curvature on the lipid membrane structure will be evaluated; (3) Photothermal heating of the membrane due to laser excitation will be calculated based on the ratio of Stokes and anti-Stokes Raman scattering; (4) The position of tryptophan residues in a model alpha helix will be studied, as well as the peptide chain and the effect on membrane structure; and (5) The membrane position and orientation of polyunsaturated fatty acids and fluorescent membrane probes, and their impact on membrane structure, will be determined.

在化学系化学测量和成像项目的支持下，莱斯大学的哈夫纳教授开发了一种测量细胞周围膜中生物分子结构的新方法。 在生物学中，生物分子的结构驱动其功能，因此测量结构是在分子尺度上理解生命的重要一步。作为膜成分的分子不溶于水，因此解析其结构是一项具有挑战性的任务。 哈夫纳和他的团队将这些分子附着在金纳米粒子上，并分析从它们散射的光。 纳米粒子将光聚焦到分子尺度。通过监测光的散射方式，可以确定分子结构。 这种新方法将用于解答理解膜在生物学中的功能的开放性问题，并帮助理解广泛用于化学和生物研究的分子探针和药物的作用。 哈夫纳教授还致力于开发有关这项研究背后的三个基本科学概念的课程材料：光波、光散射和分子振动。 开发的材料将用于莱斯大学提供的高中教师专业发展项目，该项目的大多数教师来自休斯敦独立学区（HISD）。研究团队开发了一种生物膜分子结构分析的新方法，并于最近进行了概念验证。具体来说，将脂质膜应用于溶液中的金纳米棒的表面，并记录其表面增强拉曼散射（SERS）。金纳米棒（负责增强）的电磁近场和感兴趣分子的拉曼散射张量分别通过有限元法（FEM）和时间相关密度泛函理论（TDDFT）计算。还记录了没有金纳米棒时的未增强拉曼光谱。由于近场增强的排列和快速衰减，然后通过比例分析将这些实验和理论结果结合起来，得出负责特定振动的分子成分的位置和方向。研究人员最近通过测量二油酰磷脂酰胆碱脂膜中色氨酸的位置和方向证明了这一点。具体研究目标包括：（1）建立振动标记，进一步分析脂质膜结构以及可包含的脂质种类； (2)评价纳米棒曲率对脂质膜结构的影响； (3)根据斯托克斯拉曼散射和反斯托克斯拉曼散射的比值计算激光激发引起的膜的光热加热； （4）研究色氨酸残基在模型α螺旋中的位置，以及肽链和对膜结构的影响； (5)确定多不饱和脂肪酸和荧光膜探针的膜位置和方向及其对膜结构的影响。

项目成果

A Raman spectral marker for the iso‐octyl chain structure of cholesterol

胆固醇异辛基链结构的拉曼光谱标记

• DOI: 10.1002/ansa.202300057
• 发表时间: 2023
• 期刊: Analytical Science Advances
• 作者: Simeral, Mathieu L.;Demers, Steven M. E.;Sheth, Kyle;Hafner, Jason H.
• 通讯作者: Hafner, Jason H.

Thermophoresis of gold nanorods from surface enhanced Raman scattering and real-time Rayleigh scattering in solution

• DOI: 10.1039/c9ay00104b
• 发表时间: 2019-05-14
• 期刊: ANALYTICAL METHODS
• 影响因子: 3.1
• 作者: Makihara, Takuma;Demers, Steven M. E.;Hafner, Jason H.
• 通讯作者: Hafner, Jason H.

The orientation of a membrane probe from structural analysis by enhanced Raman scattering

• DOI: 10.1016/j.bbamem.2019.183109
• 发表时间: 2020-02-01
• 期刊: BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES
• 影响因子: 3.4
• 作者: Hughes, Hannah J.;Demers, Steven M. E.;Hafner, Jason H.
• 通讯作者: Hafner, Jason H.

The Raman Active Vibrational Modes of Anthraquinones

蒽醌类化合物的拉曼主动振动模式

• DOI: 10.1089/ast.2021.0170
• 发表时间: 2022
• 期刊: Astrobiology
• 影响因子: 4.2
• 作者: Simeral, Mathieu L.;Hafner, Jason H.
• 通讯作者: Hafner, Jason H.

Improvements in Gold Nanorod Biocompatibility with Sodium Dodecyl Sulfate Stabilization

• DOI: 10.3390/jnt2030010
• 发表时间: 2021-07
• 期刊: Journal of Nanotheranostics
• 作者: Rossana Terracciano;A. Zhang;Mathieu L. Simeral;D. Demarchi;J. Hafner;Carly S. Filgueira