Malthouse J P, Gutteridge S, Bray R C
Biochem J. 1980 Mar 1;185(3):767-70. doi: 10.1042/bj1850767.
Rapid type 2 molybdenum(V) e.p.r. signals from reduced functional xanthine oxidase have been further investigated. These signals, which show strong coupling of two protons to molybdenum, have been obtained under a variety of new conditions: specifically either at pH 8.2 in the presence of borate ions, or at pH 10.1--10.7 with or without various other additions. Parameters of the signals were obtained with the help of computer simulations. In at least some of these signals, the coupled protons must be located on the enzyme rather than on bound species. The relationship between type 1 and type 2 Rapid signals is discussed. They may represent geometrical isomers, or alternatively, hydroxyl uptake as a ligand of molybdenum may be involved in formation of type 2 species.
对还原型功能性黄嘌呤氧化酶产生的快速2型钼（V）电子顺磁共振信号进行了进一步研究。这些信号显示出两个质子与钼的强耦合，已在多种新条件下获得：具体而言，要么是在pH 8.2且存在硼酸根离子的情况下，要么是在pH 10.1 - 10.7且添加或不添加各种其他物质的情况下。信号参数借助计算机模拟获得。在至少其中一些信号中，耦合质子必定位于酶上而非结合物种上。讨论了1型和2型快速信号之间的关系。它们可能代表几何异构体，或者钼作为配体摄取羟基可能参与了2型物种的形成。
