Metalloenzyme Mimics with Unsupported Metal Nanoparticle Catalysts

 描述(申请人提供)：基于配基覆盖的金属纳米颗粒扩散原理的均相催化最近引起了人们对其作为酶模拟物的潜力的更多兴趣，这是生物技术和医学研究领域中最优先的领域之一。特别是，简单的模型纳米结构材料在增强或抵抗与酶类似的特定底物的吸附方面的能力需要积极研究。我们的研究小组最近开发了一种新的催化体系，该体系对烯烃和烯烃的异构化和/或氢化具有良好的活性和选择性。考虑到它们的大小(总粒径为6-8 nm)、球形和多功能配体的特性，这些精心设计的具有活性催化金属核的有机配体修饰纳米粒子的可用性将特别有利于纳米金属酶模拟粒子的发展。例如，通过在有机配体碳氢链尾引入不同的疏水官能团，我们可以通过类似于改变酶结合口袋中氨基酸残基(侧基)的方式来调节近表面环境中的空间和/或非共价相互作用。这种方法将允许研究表面固定的配体在 通过这些分子相互作用精确调整催化选择性。拟议的四年SC3研究计划将侧重于了解近表面空间控制、非共价相互作用和手性相互作用如何决定修饰纳米颗粒对与生物重要转化(烯烃还原和异构化)相关的模型有机反应的催化性能。申请的资金用于为国际和平研究所提供暑期和学术支助，为1名毕业后研究员或技术员/年提供支助、化学品、用品、用于研究活动的实验室消耗品以及用于传播的旅费。这项工作涉及四个主要任务：1)具有近表面空间控制的金属酶模拟物，用于化学选择性和区域选择性反应。2)金属酶模拟化学选择性和区域选择性反应的非共价相互作用。3)金属酶模拟手性相互作用用于立体选择性反应。4)金属酶模拟水中生物重要反应的表面配位体的极性。这 研究计划将使PI发展基本和翻译研究技能，成为纳米材料结构控制、材料表征和生物重要转化的金属酶模拟方面的独立专家。同时，该项目将为研究生(硕士水平，每年2名学生)和本科生(4名学生/年)提供独特和令人兴奋的纳米技术研究机会。通过注册现有的基于研究的课程，学生将有机会成为跨学科研究计划的参与者，该计划将在这个项目的各个方面进行合作-从开始，从基本的纳米颗粒材料合成，到完成，直到最终 对这些新型金属酶模拟物的催化性能进行评价。他们还将培养批判性分析现有信息的智力能力，以及熟练地分析、解释和介绍复杂的数据集。派将积极地 招收女性和/或少数族裔学生，这些学生传统上在化学领域的代表性较低，以促进研究和教育的平衡发展(南加州大学被指定为西班牙裔服务机构)。PI在参与少数族裔本科生研究项目方面有着良好的记录，例如BUILD(由NIH资助的基础设施建设)，MARC(由NIH资助的少数群体进入研究职业)，RISE(由NIH资助的科学加强研究倡议)，Bridge(由NIH资助的通往文凭毕业生的桥梁)，以及目前在CSULB提供的LSAMP(路易斯·斯托克斯少数群体参与联盟项目)。

 DESCRIPTION (provided by applicant): The homogeneous catalysis based on the principle of diffusion of ligand-capped metal nanoparticles has recently drawn more interest as regards to its potential as enzyme mimics, which are one of the highest priority areas in the field of biotechnology and medical research. In particular, the ability of simple model nanostructured materials in enhancing or resisting the adsorption of particular substrates similar to that of enzymes is in needs of active investigation. Our research group has recently developed a new catalytic system that exhibits excellent activity and selectivity for the isomerization and/or hydrogenation of alkenes and alkynes. Considering their size (6-8 nm in overall particle diameter), spherical shape, and versatile ligand characteristics, the availability of these well-designed organic ligand-capped nanoparticles with active catalytic metal core will especially benefit the advancement in nanoparticle-based metalloenzyme mimics. For example, by introducing different hydrophobic functional groups in the "tail" of hydrocarbon chains of organic ligands, we can adjust steric and/or non-covalent interactions in the near-surface environment in a manner analogous to changing amino acid residues (side groups) in an enzyme binding pocket. This approach will allow the investigation of the ability of surface immobilized ligands on precisely tuning catalytic selectivity through these molecular interactions. The proposed four-year SCORE SC3 research program will focus on understanding how near-surface steric controls, non-covalent interactions, and chiral interactions determine the catalytic properties of the modified nanoparticles towards the model organic reactions relevant to the biologically important transformations (olefin reduction and isomerization). Requested funding provides summer and academic support for the PI, support for 1 post-baccalaureate fellow or technician/year, chemicals, supplies, lab consumables for research activity, and travel expenses for dissemination. The work involves four major tasks: 1) Metalloenzyme mimics with near-surface steric controls for chemo selective and regioselective reactions. 2) Metalloenzyme mimics with non-covalent interactions for chemo selective and regioselective reactions. 3) Metalloenzyme mimics with chiral interactions for stereo selective reactions. 4) Metalloenzyme mimics with controlled surface ligand polarity for biologically important reactions in water. This research plan will allow the PI to develop the basic and translational research skills to become an independent expert in nanomaterials structure controls, materials characterizations, and metalloenzyme mimics for biologically important transformations. Simultaneously, this program will provide graduate (M.S.-level, 2 students/year) and undergraduate students (4 students/year) with unique and exciting research opportunities in nanotechnology. Through enrollment in existing research-based classes, students will be offered the opportunity to be participants in an interdisciplinary research program that will collaborate on all aspects of this project - from inception, starting with basic nanoparticulate material synthesis, to completion, with the ultimate evaluation of the catalytic performance of these new metalloenzyme mimics. They will also develop the intellectual capacity to critically analyze existing information as well as develop proficiency in the analysis, interpretation and presentation of complex data sets. PI will actively recruit females and/or minority students, traditionally underrepresented groups in chemistry, to enhance the balanced advancement of research and education (CSULB is designated as a Hispanic Serving Institution). PI has a good track record of participating minority undergraduate research programs such as BUILD (Building Infrastructure Leading to Diversity funed by NIH), MARC (Minority Access to Research Careers funded by NIH), RISE (Research Initiative for Scientific Enhancement funded by NIH), BRIDGES (Bridges to the Baccalaureate funded by NIH), in addition to LSAMP (Louis Stokes Alliance for Minority Participation program funded by NSF) that are currently available in CSULB.