Molla Gianluca, Sacchi Silvia, Bernasconi Mariagrazia, Pilone Mirella S, Fukui Kiyoshi, Polegioni Loredano
Department of Biotechnology and Molecular Sciences, University of Insubria, Varese, Italy.
FEBS Lett. 2006 Apr 17;580(9):2358-64. doi: 10.1016/j.febslet.2006.03.045.
D-Amino acid oxidase (DAAO) has been proposed to be involved in the oxidation of D-serine, an allosteric activator of the NMDA-type glutamate receptor in the brain, and to be associated with the onset of schizophrenia. The recombinant human DAAO was expressed in Escherichia coli and was isolated as an active homodimeric flavoenzyme. It shows the properties of the dehydrogenase-oxidase class of flavoproteins, possesses a low kinetic efficiency, and follows a ternary complex (sequential) kinetic mechanism. In contrast to the other known DAAOs, the human enzyme is a stable homodimer even in the apoprotein form and weakly binds the cofactor in the free form.
D-氨基酸氧化酶（DAAO）被认为参与了D-丝氨酸的氧化过程，D-丝氨酸是大脑中N-甲基-D-天冬氨酸（NMDA）型谷氨酸受体的变构激活剂，且与精神分裂症的发病有关。重组人DAAO在大肠杆菌中表达，并作为一种活性同二聚体黄素酶被分离出来。它具有黄素蛋白脱氢酶-氧化酶类的特性，动力学效率较低，遵循三元复合物（有序）动力学机制。与其他已知的DAAO不同，人源酶即使以脱辅基蛋白形式存在也是稳定的同二聚体，并且以游离形式与辅因子的结合较弱。
