NMR STUDIES OF CHLOROPHYLL A IN PHOTOSYNTHETIC MEMBRANE

光合膜中叶绿素A的核磁共振研究

• 批准号: 3734243
• 负责人: PHOEBE K DEA
• 金额: --
• 依托单位: CALIFORNIA STATE UNIVERSITY LOS ANGELES
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/3734243
• 关键词: calorimetry; chemical chain length; chlorophyll; diacylglycerols; galactolipids; lipid bilayer membrane; membrane model; nuclear magnetic resonance spectroscopy; phosphatidylcholines; phospholipids; photosynthesis; porphyrin structure

Photosynthesis is one of the basic processes in nature in which the energy of sunlight is efficiently converted into chemical energy, a reaction as yet difficult to mimic in vitro. While the function of chlorophylls in the photosynthetic process is reasonably well defined, the structural organization of the light-harvesting chlorophylls in the thylakoid is a subject of considerable current interest. The proposed research extends work carried out during the previous funding period on the organization of chlorophyll alpha in dimyristoyllecithin bilayer membranes. In this project, high field deuterium (2H) NMR spectroscopy will be used as the principal technique to study the specific interactions between chlorophyll and the thylakoid lipids. 2H-NMR relaxation measurements provide an ideal means of observing slow motions in lipid bilayers. 2H is a quadrupolar nucleus, and the quadrupolar interaction dominates other spin interactions in the 2H NMR relaxation expression. In addition, the lipid hydrocarbon chains may be deuterated at a single position allowing selective observation of a particular region of the bilayer. We will use the angular dependence of the spin-spin relaxation rate (T2-1) and the dependence of T2-1 on the order parameter to characterize the nature of slow motions and to determine the contribution of director fluctuations to T2-1 in the galactolipid membrane and in the presence of chlorophyll alpha. Ancillary techniques will include optical spectroscopy and chromatography as requisite for the isolation, purification and purity determination of chlorophylls and lipids, and will include differential scanning calorimetry as an adjunct to the NMR technique. This research project should shield useful information on the phase behavior, interaction and dynamics of chlorophyll alpha in lipid membranes. The project will also provide student participants with research exposure and training in biomedical research, thereby motivating students to pursue a career in biomedical research through close counseling and supervision, as well as through group dynamics of the research project team.

光合作用是自然界的基本过程之一，在这个过程中，能量 的太阳光被有效地转化为化学能，一种反应 但在体外很难模仿。而叶绿素在植物生长发育中的作用 光合作用过程被合理地定义，结构 类囊体中捕光叶绿素的组织是一个 当前颇受关注的主题。 拟议的研究扩展了前一次资助期间开展的工作 二肉豆蔻基卵磷脂中叶绿素α的组织时期 双层膜。在这个项目中，高场氚(2H)核磁共振 光谱学将作为研究特定物质的主要技术。 叶绿素与类囊体脂的相互作用。2H-核磁共振 松弛测量提供了一种观察慢运动的理想方法 脂质双分子层。2H是一个四极核，而四极核 相互作用主导2H核磁共振弛豫中的其他自旋相互作用 表情。此外，脂族碳氢链可以在 允许选择性地观察特定区域的单一位置 双层的。我们将使用自旋-自旋的角度依赖关系 弛豫速率(T2-1)和T2-1对序参数T0的依赖关系 描述慢动作的性质并确定其贡献 在半乳脂膜上和在半乳脂膜中 叶绿素α的存在。辅助技术将包括光学 光谱和层析作为分离所必需的， 叶绿素和脂类的提纯和纯度测定 包括差示扫描量热法作为核磁共振的附件 技术。 这项研究项目应该屏蔽有关阶段的有用信息 脂膜中叶绿素α的行为、相互作用和动力学。 该项目还将为学生参与者提供研究机会。 和生物医学研究方面的培训，从而激励学生追求 通过密切的咨询和监督在生物医学研究方面的职业， 以及通过研究项目团队的群体动力。