Department of Chemistry and Biochemistry, University of Mississippi, Coulter Hall, Oxford, MS 38677, USA.
Int J Mol Sci. 2023 Jun 19;24(12):10317. doi: 10.3390/ijms241210317.
We present a Ni site model of acetyl coenzyme-A synthase (ACS) within a de novo-designed trimer peptide that self-assembles to produce a homoleptic Ni(Cys) binding motif. Spectroscopic and kinetic studies of ligand binding demonstrate that Ni binding stabilizes the peptide assembly and produces a terminal Ni-CO complex. When the CO-bound state is reacted with a methyl donor, a new species is quickly produced with new spectral features. While the metal-bound CO is albeit unactivated, the presence of the methyl donor produces an activated metal-CO complex. Selective outer sphere steric modifications demonstrate that the physical properties of the ligand-bound states are altered differently depending on the location of the steric modification above or below the Ni site.
我们提出了一个位于从头设计的三聚体肽内的乙酰辅酶 A 合酶（ACS）的 Ni 位模型，该三聚体肽自身组装以产生同配位的 Ni(Cys) 结合基序。配体结合的光谱和动力学研究表明，Ni 结合稳定了肽组装并产生末端 Ni-CO 络合物。当 CO 结合态与供甲基体反应时，会迅速产生具有新光谱特征的新物种。虽然金属结合的 CO 没有被激活，但供甲基体的存在产生了一个被激活的金属-CO 络合物。选择性的外部球体空间位阻修饰表明，配体结合态的物理性质根据位阻修饰位于 Ni 位上方或下方的位置而不同地被改变。
