Mannosidase inhibitors as therapeutics for glycoprotein misfolding diseases

甘露糖苷酶抑制剂作为糖蛋白错误折叠疾病的治疗药物

• 批准号: 7886999
• 负责人: KELLEY W. MOREMEN
• 金额: $ 8.46万
• 依托单位: UNIVERSITY OF GEORGIA
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-08-15 至 2011-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7886999
• 关键词: Address; Adverse effects; Affinity; Binding; Biochemical; Biochemistry; Biological Assay; Biological Models; Carbohydrates; Cell Maturation; Cell surface; Cells; Chemicals; Combinatorial Synthesis; Complex; Coupled; Cystic Fibrosis; Cystic Fibrosis Transmembrane Conductance Regulator; Cytoplasm; Defect; Destinations; Disease; Disease model; Effectiveness; Endoplasmic Reticulum; Enzyme Inhibition; Enzymes; Evaluation; Glycoproteins; Glycoside Hydrolases; Goals; Golgi Apparatus; Hereditary Disease; Human; Human Genetics; In Vitro; Kinetics; Lead; Lectin; Libraries; Lysosomal Storage Diseases; Lysosomes; Mannose; Mannosidase; Medicine; Modeling; Modification; Molecular Chaperones; Mutation; NIH Program Announcements; Oligosaccharides; Pathology; Play; Polysaccharides; Process; Protein C Inhibitor; Proteins; Quality Control; Recombinants; Research; Research Personnel; Role; Screening procedure; Signal Transduction; Specificity; Structure; Study models; Testing; Therapeutic; Time; Universities; analog; base; college; combinatorial; cytotoxicity; enzyme activity; high throughput screening; human disease; inhibitor/antagonist; loss of function; mutant; novel therapeutics; overexpression; polypeptide; premature; programs; protein folding; protein misfolding; residence; response; small molecule; small molecule libraries; structural biology; virtual

The long-term goals of this application are to develop selective inhibitors for an ER glycoprotein processing enzyme that plays a key role in quality control in the endoplasmic reticulum (ER) as broad-based therapeutics for glycoprotein misfolding diseases. This enzyme, ER a-mannosidase I (ERManl), acts as a key timer for ER residence for newly synthesized glycoproteins by initiating a rate-limiting step leading to a cascade of interactions that ultimately leads to the targeting of terminally misfolded glycoproteins for retrotranslocation to the cytoplasm and proteasomal disposal in a process known as "ER-associated degradation" (ERAD). Many ioss-of-function human genetic diseases result from mutations that cause delayed protein folding kinetics rather than generating terminally misfolded polypeptides. Recognition of the incompletely folded intermediates by the ERAD targeting machinery can lead to premature disposal of potentially functional glycoproteins and subsequently leads to pathology. Inhibition of the rate-determining steps in ERAD could provide a broad-based therapeutic approach for treatment of glycprotein misfolding diseases by delaying ERAD and providing sufficient time to complete the protein folding process. All of the known inhibitors of early mannose trimming steps, however, also have unacceptable serious side effects. They also inhibit glycan processing a-mannosidases in the Golgi complex and block maturation to complex type glycan structures on cell surface and secreted glycoproteins. Thus, the goals of this application are to identify selective ERManl inhibitors that can act to delay ERAD, rescue ER protein folding defects in human disease, and retain normal glycan maturation in the Golgi complex. The unique interdisciplinary team that we have assembled takes advantage of ongoing synergistic collaborative interactions between investigators at the University of Georgia and Baylor College of Medicine with expertise in the synthesis of selective glycosidase inhibitors (Boons), the biochemistry and structural biology of the ER and Golgi mannosidases (Moremen), and cell-based assays for a human glycoprotein misfolding disorder, a1-antitrypsin deficiency (Sifers). Promising leads will also be evaluated in established lysosomal storage disease models by collaborators (Amicus). Three specific aims are proposed including 1) the directed rational and combinatorial synthesis of analogs of a-mannosidase inhibitors with selectivity toward ERManl, 2) high-throughput screens combined with detailed biochemical and structural analysis to assess selectivity and effectiveness of the inhibitor compounds in blocking ERManl but not Golgi glycan maturation, and 3) cell-based assays to assess chemical chaperone effects of mannosidase inhibitors in the rescue of mutant a1-antitrypsin secretion and lysosomal enzyme targeting and without blockage of N-glycan maturation.

本申请的长期目标是开发ER糖蛋白的选择性抑制剂 加工酶，在内质网（ER）的质量控制中起着关键作用， 糖蛋白错误折叠疾病的治疗剂。这种酶，ER α-甘露糖苷酶I（ERManl），作为 新合成的糖蛋白的ER驻留的关键计时器，通过启动限速步骤，导致 级联的相互作用，最终导致靶向末端错误折叠的糖蛋白， 在称为“ER相关”的过程中， 降解”（ERAD）。许多功能丧失的人类遗传疾病是由突变引起的， 延迟蛋白质折叠动力学而不是产生末端错误折叠的多肽。承认 ERAD靶向机制不完全折叠的中间体可能导致过早处置 潜在的功能性糖蛋白，并随后导致病理学。抑制速率决定 ERAD中的步骤可以为治疗糖蛋白错误折叠提供广泛的治疗方法 通过延迟ERAD和提供足够的时间来完成蛋白质折叠过程来治疗疾病。所有 然而，已知的早期甘露糖修剪步骤的抑制剂也具有不可接受的严重副作用。 它们还抑制高尔基复合体中的聚糖加工α-甘露聚糖酶，并阻断复合体的成熟。 型聚糖结构和分泌的糖蛋白。因此，本申请的目标是 鉴定可用于延迟ERAD、拯救人ER蛋白折叠缺陷的选择性ERMan 1抑制剂 疾病，并保持正常的高尔基复合体中的聚糖成熟。 我们组建的独特的跨学科团队利用持续的协同效应， 格鲁吉亚大学和贝勒医学院的研究人员之间的合作互动 具有选择性糖苷酶抑制剂（Boons）合成的专业知识， ER和高尔基甘露聚糖酶的生物学（Moremen），以及人糖蛋白的基于细胞的测定 错误折叠病症、α 1-抗胰蛋白酶缺乏症（Sifers）。有前途的线索也将在既定的评估 溶酶体贮积病模型（Amicus）。提出了三个具体目标，包括1） 具有选择性的α-甘露糖苷酶抑制剂类似物的定向合理组合合成 2）高通量筛选结合详细的生物化学和结构分析， 评估抑制剂化合物在阻断ERManl而非高尔基体聚糖中的选择性和有效性 成熟，和3）基于细胞的测定，以评估甘露糖苷酶抑制剂的化学伴侣作用， 拯救突变体a1-抗胰蛋白酶分泌和溶酶体酶靶向且不阻断N-聚糖 成熟