MOLECULAR ANALYSIS OF A HEPATIC ENZYMOPATHY

人体肝脏对废氮的处理是至关重要的肝脏 这一途径的先天缺陷是致命的或严重的， 除非及早发现和治疗，否则会使人虚弱。 氨甲酰磷酸 合成酶I（CPSI）是一种肝线粒体酶，由 进行该尿素的初始步骤的基因组序列 周期 与该途径的所有组分一样，CPSI表现出较高的 组织特异性表达的程度。 更好地了解 CPSI缺乏症（CPSID）的病理生理学，我建议表征 来自不同地区的一些受影响患者的基因突变 种族背景。 目前在我实验室的样本来自40个 将通过基因扫描和测序技术对患者进行分析， 以确定CPSI中的分子缺陷。 为了 为了探索这些突变在体外的影响，我建议开发一种 CPSI表达载体将用于研究其结构和功能。 正常和突变蛋白的功能。 我还建议发展 一种具有体内表达潜力的真核表达载体， 替代这种必需的肝酶。 的发展 这些表达系统将提供用于调节肝细胞凋亡的模型。 酶活性，并将提供一种机制，评估药物 相互作用和药物治疗方案。

The processing of waste nitrogen in the human liver is a vital hepatic function, and inborn errors in this pathway are fatal or seriously debilitating unless recognized and treated early. Carbamyl phosphate synthetase I (CPSI) is a hepatic mitochondrial enzyme encoded by genomic sequence which carries out the initial step of this urea cycle. Like all components of the pathway, CPSI exhibits a high degree of tissue-specific expression. To better understand the pathophysiology of CPSI deficiency (CPSID), I propose to characterize the genetic mutations in a number of affected patients from diverse ethnic backgrounds. Samples currently in my laboratory from 40 patients will be analyzed by gene scanning and sequencing techniques in order to determine the molecular defects in CPSI. In order to explore the effect of these mutations in vitro, I propose developing a CPSI expression vector which will be used to study the structure and function of both normal and mutant protein. I also propose developing a eukaryotic expression vector with the potential for in vivo replacement of this essential hepatic enzyme. The development of these expression systems will provide a model for modulating hepatic enzyme activity, and will provide a mechanism for evaluating drug interactions and pharmacologic treatment regimens as well.