BIGH3 Wild-Type and Mutant Proteins

描述(由申请人提供)：角膜含有丰富的、鲜为人知的临床相关蛋白，对保持角膜透明度非常重要。TGFBI(BIGH3)基因突变是几种没有明显非眼部表现的表型不同的遗传性角膜疾病的原因。这些疾病包括几种类型的晶格状角膜营养不良和角膜淀粉样变性，颗粒性角膜营养不良，Reis-B|ockler角膜营养不良，Thiel-Behnke营养不良，以及几种非典型的角膜疾病。特定的临床和组织病理表型依赖于TGFBI的精确突变，但不同表型的分子解释仍有待确定。在这些疾病中，由TGFBI编码的突变的细胞外转化生长因子β诱导蛋白(TGFBIp)积聚在角膜基质中，显然局限于角膜。长期目标是了解这种独特蛋白质的性质，并研究TGFBI突变患者角膜中积累的特定沉积的分子机制。这项建议的具体目的是：(1)筛查遗传性角膜疾病受试者的TGFBIp突变；(2)通过激光捕获显微解剖和液-质联用(LC-MS/MS)分析从手术切除的角膜组织中分离出的异常沉积物，以确定突变的TGFBIp是否部分或全部积聚在角膜中，以及哪些其他蛋白质(S)与其密切相关。(3)测定纯化的重组野生型和致病TGFBIp的FAS4结构域的生化和生物物理性质；(4)用X射线结晶学和核磁共振技术解析重组野生型TGFBIp和重组野生型和致病突变体FAS4结构的原子分辨三维结构。与公共卫生相关。这是对一种重要的、知之甚少的蛋白质(TGFBIp)的研究。这种蛋白编码基因(TGFBIp)的突变会导致几种角膜疾病(营养不良)，对TGFBIp的更好了解将导致更好的方法来治疗由此导致的视力受损和衰弱症状。

DESCRIPTION (provided by applicant): The cornea contains an abundant poorly understood clinically relevant protein important for the preservation of corneal transparency. Mutations in the TGFBI (BIGH3) gene are responsible for several phenotypically different inherited corneal diseases that have no apparent non-ocular manifestations. These disorders include several varieties of lattice corneal dystrophy and corneal amyloidoses, granular corneal dystrophy, Reis- B|cklers corneal dystrophy, Thiel-Behnke dystrophy, and several atypical corneal disorders. The particular clinical and histopathologic phenotypes are dependent upon the precise mutation in TGFBI, but a molecular explanation for the different phenotypes remains to be determined. The mutated extracellular transforming growth factor beta induced protein (TGFBIp) encoded by TGFBI accumulates in the corneal stroma in these disorders which are apparently limited to the cornea. The long-term objectives are to understand the properties of this unique protein and to investigate the molecular mechanisms responsible for the specific deposits that accumulate within the cornea in patients with mutated TGFBI. The Specific Aims of this proposal are: (1) to screen subjects with inherited corneal diseases for TGFBI mutations, (2) to analyze abnormal deposits isolated from surgically excised corneal tissue by laser capture micro-dissection and liquid chromatography/tandem mass spectrometry (LC MS/MS) to determine whether part or all of the mutated TGFBIp accumulates in the cornea and what other protein(s) are closely linked to it, (3) to determine the biochemical and biophysical properties of the FAS4 domain of purified recombinant wild-type and disease producing TGFBIp and (4) to solve the three-dimensional structure at atomic resolution of recombinant wild- type TGFBIp and the FAS4 domains of recombinant wild-type and disease producing mutants using X-ray crystallography and nuclear magnetic resonance spectroscopy (NMR). PUBLIC HEALTH RELEVANCE. This is a study of an important poorly understood protein (TGFBIp). Mutations in the gene (TGFBI) encoding for this protein cause several corneal diseases (dystrophies) and a better understanding of TGFBIp will lead to better methods of treating the resulting impaired vision and debilitating symptoms.