Departamento de Química e Bioquímica, Centro de Química e Bioquímica, Faculdade de Ciências da Universidade de Lisboa, Campo-Grande, Lisboa, Portugal.
Amyloid. 2009 Dec;16(4):201-7. doi: 10.3109/13506120903421561.
Transthyretin (TTR) is a homotetrameric protein involved in thyroid hormone transport in blood and in retinol binding in the central nervous system. More than 80 point mutations in this protein are known to be associated with the formation of amyloid deposits and systemic amyloidotic pathologies. Age at onset varies according to the mutation but considerable variations also occur for subjects carrying the same mutation. Moreover, wild-type TTR forms amyloid deposits in systemic senile amyloidosis, a geriatric disorder. An accurate diagnostic and the choice of therapeutic options depend on the identification of the specific mutation. Previous characterization of TTR variants by mass spectrometry required the use of antibodies for sample enrichment. We developed a novel assay based on ultra high-resolution mass spectrometry to identify human TTR variants. The method, requiring a very low sample amount, is based on SDS-PAGE fractionation of human serum, followed by peptide mass fingerprinting by MALDI-FTICR-MS (matrix assisted laser desorption ionization coupled to Fourier transform ion cyclotron resonance mass spectrometry). Moreover, it is possible to perform a relative quantification of wild type and mutant TTR forms by mass spectrometry. The method was tested and validated with the V30M mutant, involved in familial amyloidotic neuropathy of Portuguese type.
转甲状腺素蛋白（TTR）是一种四聚体蛋白，参与血液中甲状腺激素的转运和中枢神经系统中视黄醇的结合。该蛋白的 80 多个点突变与淀粉样沉积物的形成和全身性淀粉样变病理学有关。发病年龄因突变而异，但携带相同突变的患者也存在相当大的差异。此外，野生型 TTR 在全身性老年性淀粉样变性（一种老年疾病）中形成淀粉样沉积物。准确的诊断和治疗方案的选择取决于特定突变的识别。以前通过质谱法对 TTR 变体的表征需要使用抗体进行样品富集。我们开发了一种基于超高效分辨率质谱法的新型检测方法，用于鉴定人 TTR 变体。该方法需要的样品量非常少，基于 SDS-PAGE 分离人血清，然后通过 MALDI-FTICR-MS（基质辅助激光解吸电离与傅里叶变换离子回旋共振质谱联用）进行肽质量指纹图谱分析。此外，还可以通过质谱法对野生型和突变型 TTR 形式进行相对定量。该方法使用涉及葡萄牙家族性淀粉样多发性神经病的 V30M 突变进行了测试和验证。
