Saul Philip, Mamone Salvatore, Glöggler Stefan
NMR Signal Enhancement Group , Max-Planck-Institutefor Biophysical Chemistry , Am Faßberg 11 , 37077 Göttingen , Germany . Email:
Center for Biostructural Imaging of Neurodegeneration of UMG , Von-Siebold-Straße 3A , 37075 Göttingen , Germany.
Chem Sci. 2018 Oct 25;10(2):413-417. doi: 10.1039/c8sc02831a. eCollection 2019 Jan 14.
Magnetic resonance (NMR) is a powerful tool in chemical analysis, structure determination and in medical diagnostics. Developing novel biological sensors for this field holds promise to better investigate protein structures or target diseases more efficiently. Herein, we explore nuclear spin singlet states in dendritic macromolecules as a platform molecule to develop stimuli responsive probes. We have developed a nuclear singlet multimer (NUSIMER) based on a generation 5 poly(amidoamine) dendrimer (PAMAM) which contains on average about 90 accessible nuclear spin singlet states with lifetimes up to 10-fold longer than the relaxation times (up to 10 seconds < 0.5 seconds) in a single molecule. We demonstrate little influence on the singlet lifetime in phosphate buffer (HO) and a high viscosity gel environment in the presence of paramagnetic oxygen. Additionally, we demonstrate an increase in singlet lifetime upon the release of a protective chemical moiety from the NUSIMER following a stimulus, whereby no change in longitudinal relaxation time is observed. The robustness and change in singlet lifetime of the NUSIMER holds promise for the development of a novel type of biosensors.
磁共振（NMR）是化学分析、结构测定及医学诊断领域的强大工具。为该领域开发新型生物传感器有望更高效地深入研究蛋白质结构或靶向疾病。在此，我们探索树枝状大分子中的核自旋单重态作为开发刺激响应探针的平台分子。我们基于第5代聚（酰胺胺）树枝状大分子（PAMAM）开发了一种核单重态多聚体（NUSIMER），其平均含有约90个可及的核自旋单重态，寿命比单个分子中的弛豫时间长10倍（长达10秒，而<0.5秒）。我们证明在存在顺磁性氧的情况下，磷酸盐缓冲液（HO）和高粘度凝胶环境对单重态寿命影响很小。此外，我们证明在受到刺激后，NUSIMER释放保护性化学部分时单重态寿命增加，而纵向弛豫时间未观察到变化。NUSIMER的稳健性和单重态寿命变化为新型生物传感器的开发带来了希望。
