Effect of ligand binding on human D-amino acid oxidase: Implications for the development of new drugs for schizophrenia treatment
Effect of ligand binding on human D-amino acid oxidase: Implications for the development of new drugs for schizophrenia treatment
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DOI：
10.1002/pro.429
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发表时间：
2010-08-01
期刊：
影响因子：
8
通讯作者：
Pollegioni, Loredano
中科院分区：
文献类型：
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作者：
Caldinelli, Laura;Molla, Gianluca;Pollegioni, Loredano
在人脑中，黄素蛋白D-氨基酸氧化酶（hDAAO）负责降解神经调质D-丝氨酸，D-丝氨酸是NMDA受体介导的神经传递的重要效应物。实验证据支持通过hDAAO抑制增加E-丝氨酸浓度可能代表改善精神分裂症患者症状的有价值的治疗方法的概念。本研究调查了底物D-丝氨酸（或假底物三氟-D-丙氨酸）、FAD辅因子和两种抑制剂（苯甲酸盐，一种经典的底物竞争性抑制剂和药物氯丙嗪（CPZ），与辅因子竞争）对hDAAO构象和稳定性的影响。我们证明了所有这些化合物都不改变hDAAO与其生理伴侣pLG 72的相互作用。所用的配体影响hDAAO的三级结构不同：苯甲酸酯或三氟-D-丙氨酸结合增加了溶液中全酶形式的量并稳定了黄素蛋白，而CPZ结合有利于类似于脱辅基蛋白的蛋白质构象，其对降解更敏感。有趣的是，hDAAO的脱辅基蛋白形式结合底物E-丝氨酸：这种相互作用增加FAD结合，从而增加溶液中活性全酶的量。苯甲酸盐和CPZ类似地改变短期细胞D-丝氨酸浓度，但不同地影响hDAAO的细胞浓度。总之，所用配体对hDAAO构象和稳定性的不同改变代表了在开发科普精神分裂症的新药期间需要考虑的另一个参数。
In human brain the flavoprotein D-amino acid oxidase (hDAAO) is responsible for the degradation of the neuromodulator D-serine, an important effector of NMDA-receptor mediated neurotransmission. Experimental evidence supports the concept that E-serine concentration increase by hDAAO inhibition may represent a valuable therapeutic approach to improve the symptoms in schizophrenia patients. This study investigated the effects on hDAAO conformation and stability of the substrate D-serine (or of the pseudo-substrate trifluoro-D-alanine), the FAD cofactor, and two inhibitors (benzoate, a classical substrate-competitive inhibitor and the drug chlorpromazine (CPZ), which competes with the cofactor). We demonstrated that all these compounds do not alter the interaction of hDAAO with its physiological partner pLG72. The ligands used affect the tertiary structure of hDAAO differently: benzoate or trifluoro-D-alanine binding increases the amount of the holoenzyme form in solution and stabilizes the flavoprotein, while CPZ binding favors a protein conformation resembling that of the apoprotein, which is more sensitive to degradation. Interestingly, the apoprotein form of hDAAO binds the substrate E-serine: this interaction increases FAD binding thus increasing the amount of active holoenzyme in solution. Benzoate and CPZ similarly modify the short-term cellular D-serine concentration but affect the cellular concentration of hDAAO differently. In conclusion, the different alteration of hDAAO conformation and stability by the ligands used represents a further parameter to take into consideration during the development of new drugs to cope schizophrenia.