Kaster Megan A, Caldwell Michael A, Roach Caroline M, Bailey Matthew D, Meade Thomas J
Departments of Chemistry, Molecular Biosciences, Neurobiology and Radiology, Northwestern University, 2145 N. Sheridan Road, Evanston, Illinois 60208, United States.
Inorg Chem. 2025 Jul 28;64(29):14785-14798. doi: 10.1021/acs.inorgchem.5c00798. Epub 2025 Jul 11.
Spectroscopic detection of paramagnetically shifted H signals of trivalent lanthanide complexes provide a means for ratiometric detection of enzymatic activity. Herein, we report on the synthesis and characterization of , , and complexes for ratiometric detection of the enzyme nitroreductase (NTR). Ln(III) coordination environments with distinct - and - probe states provide unique paramagnetic contributions to the chemical shift of a 5-(Bu)-pyridine-based reporter group for quantitative detection of enzyme activity. The paramagnetic contribution to chemical shift from Tb(III) and Dy(III) shift the H chemical signal beyond the background region to low frequencies (δ < -15) for zero background signal. Paramagnetic relaxation enhancement of reporter group protons enables the development of probe-specific pulse sequences with short acquisition and delay times. A probe-specific pulse sequence for acquired 256 scans in under 1 min and enabled ratiometric detection of NTR activity.
三价镧系配合物顺磁位移氢信号的光谱检测为酶活性的比率检测提供了一种方法。在此，我们报告了用于比率检测硝基还原酶（NTR）的 、 和 配合物的合成与表征。具有不同 - 和 - 探针状态的Ln(III)配位环境为基于5-(Bu)-吡啶的报告基团的化学位移提供了独特的顺磁贡献，用于酶活性的定量检测。来自Tb(III)和Dy(III)的对化学位移的顺磁贡献将氢化学信号移至背景区域之外，达到低频（δ < -15）以实现零背景信号。报告基团质子的顺磁弛豫增强使得能够开发具有短采集和延迟时间的探针特异性脉冲序列。用于 的探针特异性脉冲序列在不到1分钟的时间内采集了256次扫描，并实现了NTR活性的比率检测。
