Magnetic Resonance Center CERM, University of Florence, Via Luigi Sacconi 6, 50019, Sesto Fiorentino, Florence, Italy; Department of Chemistry, University of Florence, Via della Lastruccia 3, 50019 Sesto Fiorentino, Florence, Italy.
Magnetic Resonance Center CERM, University of Florence, Via Luigi Sacconi 6, 50019, Sesto Fiorentino, Florence, Italy; Department of Chemistry, University of Florence, Via della Lastruccia 3, 50019 Sesto Fiorentino, Florence, Italy.
J Mol Biol. 2019 Nov 8;431(22):4514-4522. doi: 10.1016/j.jmb.2019.08.018. Epub 2019 Sep 4.
Iron-sulfur clusters in radical S-adenosylmethionine (SAM) enzymes catalyze an astonishing array of complex and chemically challenging reactions across all domains of life. Here we showed that H NMR spectroscopy experiments tailored to reveal hyperfine-shifted signals of metal-ligands is a powerful tool to monitor the binding of SAM and of the octanoyl-peptide substrate to the two [4Fe-4S] clusters of human lipoyl synthase. The paramagnetically shifted signals of the iron-ligands were specifically assigned to each of the two bound [4Fe-4S] clusters, and then used to examine the interaction of SAM and substrate molecules with each of the two [4Fe-4S] clusters of human lipoyl synthase. H NMR spectroscopy can therefore contribute to the description of the catalityc mechanism of radical SAM enzymes.
铁硫簇在自由基 S-腺苷甲硫氨酸（SAM）酶中催化了生命所有领域中一系列惊人的复杂和具有挑战性的化学反应。在这里，我们表明，专门设计用于揭示金属配体超精细位移信号的 H NMR 光谱实验是一种强大的工具，可以监测 SAM 和辛酰肽底物与两种人脂酰基辅酶 A 合成酶的[4Fe-4S]簇的结合。铁配体的顺磁位移信号被专门分配给两个结合的[4Fe-4S]簇中的每一个，然后用于研究 SAM 和底物分子与两种人脂酰基辅酶 A 合成酶的[4Fe-4S]簇中的每一个的相互作用。因此，H NMR 光谱可以为自由基 SAM 酶的催化机制的描述做出贡献。
