Collaborative Research: A Multi-Disciplinary Study of Selective Adsorption of Chiral Molecules on Mineral Surfaces

合作研究：手性分子在矿物表面选择性吸附的多学科研究

• 批准号: 0229634
• 负责人: Robert Hazen
• 金额: $ 9.57万
• 依托单位: Carnegie Institution of Washington
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-01-01 至 2004-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0229634&HistoricalAwards=false
• 关键词: Collaborative; Research; Multi; Disciplinary; Study

ABSTRACTSelective adsorption of aqueous solutes onto mineral surfaces represents an important mechanism for the concentration, sequestration and organization of organic molecules. Such mineral-organic interactions play key roles in processes as diverse as aquifer purification, biofilm formation and the origin of life.In this regard, the selective adsorption of chiral (left-handed versus right-handed) molecules is of special interest. Strong chiral preference for amino acids, sugars and other essential biomolecules is a defining characteristic of biological systems. Abiotic processes that select left-handed versus right-handed molecules are thus central to geochemical models of life's origin. Chiral recognition and separation of molecules, furthermore, is vital to pharmacological activity of many drugs, biodegradation of packaging materials, development of improved polymers, and many other applications in science and industry.Previous work described selective adsorption of D- and L-aspartic acid, a biological amino acid, on chiral crystal growth faces of calcite. Such chiral selectivity on surfaces of a centric mineral had been predicted by theory, but had not been demonstrated experimentally. This proposal seeks to document further this behavior and to investigate structural mechanisms by which chiral organic molecules adsorb selectively on mineral surfaces. A multi-disciplinary, collaborative, two-part research program includes:I. Phenomenology of Chiral Adsorption on Minerals: Research will expand on previous studies, which demonstrated chiral selectivity on mineral surfaces, by establishing the range and extent of chiral adsorption on mineral surfaces. Proposed experiments include:1. Investigation of the adsorption of other chiral amino acids, both biological and non-biological, onto calcite crystal growth surfaces.2. Investigation of the adsorption of chiral amino acid derivatives, sugars, nucleotides and other chiral species onto calcite crystal growth surfaces.3. Investigation of chiral adsorption onto crystal growth surfaces of gypsum and quartz, both of which are geochemically important minerals that display chiral crystal growth surfaces.II. Adsorption Mechanisms - Experimental Approaches: Structural mechanisms that underlie chiral adsorption of organic molecules on these mineral surfaces will be investigated. Proposed experiments include:1. Liquid-immersion atomic force microscopy imaging of calcite crystal growth surfaces: Observations will be made of both surface growth and dissolution in the presence and absence of chiral adsorbates.2. Use of site-specific fluorescent tags: Calcite surfaces with an adsorbed layer of amino acids will be exposed to a variety of fluorescent tags to determine the orientation and distribution of adsorbed molecules.These proposed studies, in concert with ongoing theoretical models of the adsorption process, will lead to an understanding of structural mechanisms of chiral selection. This work, furthermore, will lay the groundwork for future investigations that adaptmicroarray technology to the combinatorial study numerous of mineral surfaces and adsorbed organic species in a single experiment.

水溶质在矿物表面的选择性吸附是有机分子浓缩、隔离和组织的重要机制。这种矿物-有机相互作用在含水层净化、生物膜形成和生命起源等过程中起着关键作用。在这方面，手性(左手和右手)分子的选择性吸附是特别感兴趣的。对氨基酸、糖和其他基本生物分子的强烈手性偏好是生物系统的一个重要特征。因此，选择左手分子而不是右手分子的非生物过程是生命起源的地球化学模型的核心。此外，分子的手性识别和分离对于许多药物的药理活性、包装材料的生物降解、改性聚合物的开发等许多科学和工业应用都是至关重要的。以前的工作描述了生物氨基酸D-和L-天冬氨酸在方解石手性晶体生长面上的选择性吸附。这种在中心矿物表面的手性选择性已经从理论上得到了预测，但尚未在实验上得到证实。这项提议试图进一步记录这一行为，并研究手性有机分子选择性吸附在矿物表面的结构机制。一项多学科、协作、分两部分的研究计划包括：1.矿物上手性吸附的现象学：通过建立矿物表面上手性吸附的范围和程度，研究将在以前的研究基础上进行扩展，这些研究证明了矿物表面上的手性选择性。拟做的实验包括：1.研究其他手性氨基酸，包括生物和非生物氨基酸在方解石晶体生长表面的吸附。考察了手性氨基酸衍生物、糖、核苷酸等手性物种在方解石晶体生长表面上的吸附。研究石膏和石英在晶体生长表面上的手性吸附，这两种矿物都是具有手性晶体生长表面的重要矿物。II.吸附机理-实验方法：将研究有机分子在这些矿物表面上手性吸附的结构机理。建议的实验包括：1.方解石晶体生长表面的液浸原子力显微镜成像：在存在和不存在手性吸附的情况下，观察表面生长和溶解。特定部位荧光标记的使用：方解石表面吸附了一层氨基酸，将暴露在各种荧光标记下，以确定吸附分子的方向和分布。这些拟议的研究与正在进行的吸附过程理论模型相结合，将有助于理解手性选择的结构机制。此外，这项工作还将为将来将微阵列技术应用于单一实验中大量矿物表面和吸附的有机物种的组合研究奠定基础。