Proshlyakov Denis A, Farrugia Mark A, Proshlyakov Yegor D, Hausinger Robert P
Department of Physiology, Michigan State University, Michigan State University, East Lansing, Michigan 48824, United States.
Department of Chemistry, Michigan State University, Michigan State University, East Lansing, Michigan 48824, United States.
Coord Chem Rev. 2021 Dec 1;448. doi: 10.1016/j.ccr.2021.214190. Epub 2021 Sep 9.
Conventional ureases possess dinuclear nickel active sites that are oxygen-stable and require a set of accessory proteins for metallocenter biosynthesis. By contrast, oxygen-labile ureases have active sites containing dual ferrous ions and lack a requirement for maturation proteins. The structures of the two types of urease are remarkably similar, with an active site architecture that includes two imidazoles and a carboxylate ligand coordinated to one metal, two imidazoles coordinated to the second metal, and a metal-bridging carbamylated lysine ligand. The electronic spectrum of the diferric form of the enzyme resembles that of methemerythrin. Resonance Raman spectroscopic analyses confirm the presence of a μ-oxo ligand and indicate the presence of one or more terminal solvent ligands.
传统脲酶具有双核镍活性位点，这些位点对氧稳定，且金属中心生物合成需要一组辅助蛋白。相比之下，对氧不稳定的脲酶具有含双亚铁离子的活性位点，且不需要成熟蛋白。这两种类型的脲酶结构非常相似，其活性位点结构包括两个咪唑和一个与一种金属配位的羧酸盐配体、两个与第二种金属配位的咪唑，以及一个金属桥连的氨甲酰化赖氨酸配体。该酶的二铁形式的电子光谱类似于高铁肌红蛋白的电子光谱。共振拉曼光谱分析证实了μ-氧配体的存在，并表明存在一个或多个末端溶剂配体。
