Mandal Ratnamala, Pham Pierce, Hilty Christian
Department of Chemistry, Texas A&M University 3255 TAMU College Station TX 77843 USA
Chem Sci. 2021 Aug 31;12(39):12950-12958. doi: 10.1039/d1sc03404a. eCollection 2021 Oct 13.
Nuclear spin hyperpolarization through signal amplification by reversible exchange (SABRE), the non-hydrogenative version of -hydrogen induced polarization, is demonstrated to enhance sensitivity for the detection of biomacromolecular interactions. A target ligand for the enzyme trypsin includes the binding motif for the protein, and at a distant location a heterocyclic nitrogen atom for interacting with a SABRE polarization transfer catalyst. This molecule, 4-amidinopyridine, is hyperpolarized with 50% -hydrogen to yield enhancement values ranging from -87 and -34 in the and positions of the heterocyclic nitrogen, to -230 and -110, for different solution conditions. Ligand binding is identified by flow-NMR, in a two-step process that separately optimizes the polarization transfer in methanol while detecting the interaction in a predominantly aqueous medium. A single scan Carr-Purcell-Meiboom-Gill (CPMG) experiment identifies binding by the change in relaxation rate. The SABRE hyperpolarization technique provides a cost effective means to enhance NMR of biological systems, for the identification of protein-ligand interactions and other applications.
通过可逆交换信号放大（SABRE）实现的核自旋超极化，即氢诱导极化的非氢化版本，被证明可提高检测生物大分子相互作用的灵敏度。胰蛋白酶的目标配体包含该蛋白质的结合基序，并且在远处有一个杂环氮原子用于与SABRE极化转移催化剂相互作用。该分子4-脒基吡啶用50%的氢进行超极化，在不同溶液条件下，杂环氮的α和β位置的增强值范围从-87和-34到-230和-110。配体结合通过流动核磁共振在两步过程中识别，该过程在甲醇中分别优化极化转移，同时在主要为水的介质中检测相互作用。单次扫描的 Carr-Purcell-Meiboom-Gill（CPMG）实验通过α弛豫率的变化识别结合。SABRE超极化技术为增强生物系统的核磁共振提供了一种经济有效的方法，用于鉴定蛋白质-配体相互作用及其他应用。
