“Spin-Torch NMR”: Transfer of nuclear hyperpolarization to explore molecular environment

光合作用电子泵发生在称为反应中心(RCS)的蛋白质中。在这里，(细菌)叶绿素辅助因子在一个高度优化的环境中吸收光和前向电子。光致自旋相关自由基对(SCRP)中的自旋演化允许通过固态光致CIDNP效应增强核磁共振信号。发生在自由基对的13C和15N核上的瞬时超极化将被用来探索分子环境。我们将确定化学位移、化学位移各向异性(CSA)、弛豫参数、局部动力学和距离。这些转移方案将被进一步开发并应用于两种不同的光合作用RCS：紫细菌和日光细菌的RCS。比较可能允许识别常见的功能模式。在未来，有了人工RCS，这里开发的转移方案也将允许进行表面研究。

Photosynthetic electron pumping occurs in proteins called reaction centers (RCs). Here, (bacterio)chlorophyll cofactors absorb light and forward electrons in a highly optimized environment. Spin-evolution in the light-induced spin-correlated radical pair (SCRP) allows for NMR signal enhancement via the solid-state photo-CIDNP effect. The transient hyperpolarization, occurring on 13C and 15N nuclei in the radical pair, will be used to explore the molecular environment. We will determine chemical shifts, chemical shift anisotropies (CSAs), relaxation parameters, local dynamics and distances. These transfer schemes will be further developed and applied to two different photosynthetic RCs: Those of purplebacteria and of heliobacteria. Comparison might allow to recognize common functional patterns. In future, having artificial RCs, the transfer schemes developed here will allow for surface studies, too.