EAGER: Illuminating the consequences of membrane association on quantum-based magnetosensing

EAGER：阐明膜关联对基于量子磁传感的影响

• 批准号: 2228975
• 负责人: Lauren Jarocha
• 金额: $ 29.7万
• 依托单位: Furman University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-07-01 至 2024-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2228975&HistoricalAwards=false
• 关键词: EAGER; Illuminating; consequences; membrane; association

The proposed project is aiming to understand the roles of magnetoreception in the biological systems. Magnetoreception is a biological sense employed by migratory birds to navigate on a global scale. It has been proposed that the primary detector is a specialized ocular photoreceptor that plays host to magnetically sensitive photochemical reactions having radical pairs as fleeting intermediates. A radical pair is a short-lived reaction intermediate comprising two radicals (radical is an atom, molecule, or ion that has unpaired valence electrons or an open electron shell) formed in tandem whose unpaired electron spins may be either antiparallel (a singlet state) or parallel (a triplet state). Quantum interaction of unpaired spins can generate Magnetic Field Effects – a difference in product yield or reaction rate as a function of the field strength. The open question is whether this mechanism is the foundation of avian magnetoreception. The objective of the proposed work is to develop methodology to measure magnetic field effects on chemical reactions occurring in the photoreceptor molecules. The PI is partnered with the Osher Lifelong Learning Institute (OLLI), a learning community for senior learners, to offer classes on quantum mechanics and quantum biology. OLLI offers 150 courses and 40 additional events per year that are available to nearly 2600 members. The Co-PI will present on magnetism and chemical sensing at the Western Region Education Service Alliance’s STEM Entrepreneurship program, a biannual event that engages elementary, middle, and high school students from 18 school systems across eight counties in western North Carolina. These activities lead to dissemination of research results to the public across a wide range of ages and backgrounds, with the goal of increasing scientific literacy and engagement in the local community.The long-term goal of this project is to provide evidence that avian magnetoreception is a quantum phenomenon. To act as a directional sensor, Cryptochrome proteins (chemistry of Cryptochrome, a blue-light photoreceptor protein found in the avian retina, are speculated to be responsible for magnetic sensing) must be oriented. For radical pairs formed in Cryptochrome to act as a magnetoreceptor, they must demonstrate sensitivity to external fields, including those as weak as the Earth’s natural field of 50-100 μT, and that sensitivity must have a direction dependence. Furthermore, in vitro studies suggest that increasing viscosity leads to an increase in magnetic sensitivity. Lipid membrane association is a promising way to achieve both requirements. The main objective of the proposed work is to develop an evanescent-wave cavity enhanced spectrometer to measure magnetic field effects on chemical reactions occurring between membrane-bound molecules. The central hypothesis is that membrane association transforms a radical pair magnetosensor into a molecular compass that can sense Earth strength fields. If successful, the project will allow the field to demonstrate anisotropic magnetic field effects on biomolecules – including Cryptochrome. From an ecological perspective, understanding the mechanism of avian navigation is important to protect migratory birds. Beyond that, if the quantum origin of this phenomenon proves correct, the principles of its operation can inform the design of navigational devices as alternatives to satellite-based global positioning systems.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

该项目旨在了解磁感受在生物系统中的作用。磁感受是候鸟在全球范围内导航的一种生物感觉。有人提出，主要的检测器是一个专门的眼睛感光器，发挥主机磁敏感的光化学反应，自由基对作为短暂的中间体。自由基对是一种短寿命的反应中间体，包括串联形成的两个自由基（自由基是具有未成对价电子或开放电子壳层的原子、分子或离子），其未成对电子自旋可以是反平行的（单线态）或平行的（三线态）。不成对自旋的量子相互作用可以产生磁场效应-产物产率或反应速率的差异作为场强的函数。悬而未决的问题是，这种机制是否是鸟类磁感受的基础。所提出的工作的目的是开发方法来测量磁场对感光分子中发生的化学反应的影响。PI与Osher终身学习研究所（OLLI）合作，这是一个面向高级学习者的学习社区，提供量子力学和量子生物学课程。OLLI每年提供150门课程和40项额外活动，可供近2600名会员使用。Co-PI将在西部地区教育服务联盟的STEM创业计划中介绍磁性和化学传感，该计划是一年两次的活动，吸引了来自北卡罗来纳州西部八个县的18所学校系统的小学，初中和高中学生。通过这些活动，向不同年龄和背景的公众传播研究成果，以提高科学素养和参与当地社区。该项目的长期目标是提供证据，证明鸟类的磁感受是一种量子现象。作为一个方向传感器，隐花色素蛋白（隐花色素的化学，一种在鸟类视网膜中发现的蓝光感光蛋白，被推测负责磁感应）必须定向。对于隐花色素中形成的自由基对作为磁感受器，它们必须表现出对外部场的敏感性，包括那些弱到50-100 μT的地球自然场，并且这种敏感性必须具有方向依赖性。此外，体外研究表明，增加粘度导致磁敏感性增加。脂质膜缔合是实现这两个要求的有希望的方式。拟议的工作的主要目标是开发一个倏逝波腔增强光谱仪来测量磁场对膜结合分子之间发生的化学反应的影响。核心假设是，膜缔合将一个自由基对磁传感器转变为一个可以感知地球强度场的分子罗盘。如果成功，该项目将允许该领域展示生物分子的各向异性磁场效应-包括隐花色素。从生态学的角度来看，了解鸟类的导航机制对保护候鸟具有重要意义。除此之外，如果这一现象的量子起源被证明是正确的，其操作原理可以为导航设备的设计提供信息，作为基于卫星的全球定位系统的替代品。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估来支持。