Structure-Based Design of Small Molecules for Aspartylglucosaminuria

基于结构的天冬氨葡萄糖胺尿小分子设计

基本信息

批准号：
8239512
负责人：
Hwai-Chen Guo
金额：
$ 25.24万
依托单位：
UNIVERSITY OF MASSACHUSETTS LOWELL
依托单位国家：
美国
项目类别：
财政年份：
2008
资助国家：
美国
起止时间：
2008-02-01 至 2015-01-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8239512
关键词：
Acetates Alleles Amino Acids Aspartylglucosaminuria Aspartylglucosylaminase Bicarbonates Binding Biochemical Carbohydrate Linkages Clinical Complex Connective Tissue Coupled Crystallization Defect Development Disease Early treatment Enzyme Precursors Enzymes Face Failure Family Foundations Genes Glycine Glycoprotein Degradation Pathway Glycoproteins Hereditary Disease Human Hydrolase Hydrolysis Ions Lesion Link Lysosomal Storage Diseases Lysosomes Mental Retardation Metabolic Metabolic Diseases Methods Molecular Mutation N-terminal Names Neonatal Screening Neuraxis Oligosaccharides Pathogenesis Patients Peptides Pharmaceutical Preparations Proteins Publishing Reporting Research Personnel Resolution Site Solid Solvents Structure Surface Symptoms Therapeutic Threonine Variant base cell type design functional group glycoasparagines inhibitor/antagonist mutant prevent programs progressive neurodegeneration protein structure skeletal abnormality small molecule

项目摘要

Aspartylglucosaminuria (AGU) is a lysosomal storage disease caused by a metabolic disorder in glycoprotein degradation. AGU results in accumulation of glycoasparagines in the lysosomes of virtually all cell types, with severe clinical symptoms such as progressive neurodegeneration and mental retardation, coarse facial features, skeletal abnormalities, and connective tissue lesions. AGU mutations occur in the gene for glycosylasparaginase (GA), a lysosomal enzyme required to hydrolyze glycoasparagines. AGU has been reported worldwide, with 26 different AGU alleles found so far, but still no treatment available for this disease. However, during the past few years, there has been significant progress in the identification and characterization of AGU causative mutations. Thus development of an effective AGU therapy would make this genetic disease amenable to newborn screening for an early treatment. Our crystallographic studies on GA reveal that a surface loop (named precursor P-loop) blocks the catalytic center of mature hydrolase. Autoproteolysis is thus required to remove this P-loop in order to open up the catalytic center. Nonetheless, AGU mutations cause misprocessing and mistargeting of GA precursors, thus prevents their autoactivation for the hydrolase activity. High-resolution structural studies of GA and AGU molecules will greatly enhance our understanding of the structural consequences of these AGU mutations but have so far been hampered by the inability to obtain sufficient amounts of highly purified human GA. Nonetheless, we have overcome this hurdle by purifying and crystallizing bacterial GA, which has been demonstrated to have identical structural features and use the same mechanism to autoactivate its hydrolase activity. Our preliminary results indicate that small molecules with structures similar to glycine can enhance autoproteolytic and hydrolase activity of AGU mutants. Building on our recent progress on GA autoprocessing, we propose in this application to 1) characterize molecular pathogenesis of AGU mutations; 2) push forward our structural and mechanistic studies of GA autoproteolytic activation; 3) study structural consequences of AGU mutations; and 4) develop small molecules to stimulate autoprocessing of AGU molecules. The broad, long- term objective of this application is to develop small molecules as therapeutics to ameliorate the AGU misprocessing and mistargeting defect and thus alleviate the suffering of AGU patients and their families.

天冬氨酸葡萄糖膜（AGU）是由代谢疾病引起的一种溶酶体储存疾病糖蛋白降解。 AGU导致在几乎所有的溶酶体中积累糖叠素细胞类型，具有严重的临床症状，例如进行性神经退行性和智力低下，粗面特征，骨骼异常和结缔组织病变。 AGU突变发生在糖基半冬酰胺酶（GA）的基因，这是水解甘草呈帕拉胶所需的溶酶体酶。 Agu拥有据报道，全球据报，到目前为止发现了26个不同的AGU等位基因，但仍然没有可用的治疗方法疾病。但是，在过去的几年中，识别和 AGU致病突变的表征。因此，开发有效的AGU疗法将使这种遗传疾病可用于新生儿筛查以进行早期治疗。我们的晶体学研究 GA揭示了表面环（命名为前体P环）阻断成熟水解酶的催化中心。因此，需要自动溶解以去除此P环以打开催化中心。尽管如此， AGU突变会导致GA先前的错误处理和误导，从而防止其自动激活用于水解酶活性。 GA和AGU分子的高分辨率结构研究将大大增强我们对这些AGU突变的结构后果的理解，但到目前为止受到了阻碍通过无法获得足够数量的高度纯化的人类GA。尽管如此，我们已经克服了通过纯化和结晶细菌GA的障碍，已被证明具有相同结构特征并使用相同的机制自动活化其水解酶活性。我们的初步结果表明，具有类似甘氨酸的结构的小分子可以增强自溶解和 AGU突变体的水解酶活性。在我们最近在GA自动处理方面的进展的基础上，我们提出了该应用于1）表征AGU突变的分子发病机理； 2）推动我们的结构和GA自传溶解激活的机械研究； 3）研究AGU的结构后果突变； 4）开发小分子以刺激AGU分子的自动化。宽阔，长期该应用的术语目标是开发小分子作为治疗剂来改善AGU 错误处理和误导缺陷，从而减轻AGU患者及其家人的苦难。