系统性老年性淀粉样变患者血清转甲状腺素蛋白出现三种修饰基团减少

目的:探讨转甲状腺素（TTR）蛋白代谢修饰与淀粉样变形成的分子机制。方法:本研究首先利用ProteomeLabPF-2D系统依据蛋白质等电点分选各个pH值范围蛋白质，然后利用抗人TTR抗体，点免疫印迹实现鉴定TTR蛋白存在于被收集的范围。利用硫黄素T（ThT）试剂，测定各个收集部分溶液中淀粉样变的含量，进一步利用飞行质谱的表面增强激光解吸/电离时间（SELDI-TOF-MS）分析各个部分TTR蛋白的修饰类型。结果:系统性老年性淀粉样变（SSA）患者和健康志愿者血清pH范围分别为 8.1～8.0，4.0～4.6及6.8～5.8范围时出现高丰度蛋白。并且SSA患者pH6.8~5.8范围淀粉样变含量明显高于对照组（P＜0.05），其中SSA组与健康组相比，血TTR 蛋白N端氨基酸修饰基团包括磷酰基（Phosphoryl）、羟基（Hydroxyl）、葡萄糖胺（O-GlcNac）基团修饰阴性。结论:SSA患者血TTR 蛋白N端氨基酸修饰基团Phosphoryl、Hydroxyl、O-GlcNac的减少可能与淀粉样蛋白的形成有关。

Three modified groups to decrease in serum transthyroxine protein in patients with systemic senile amyloidosis

Objective: To explore TTR event protein metabolism and the molecular mechanism of amyloid formation. Methods: We first used ProteomeLabPF - 2D system to separate protein on the basis of protein isoelectric point(IP) in each pH range and then western blot was applied to identify the TTR range. We used sulfur flavin T (ThT) reagent quantitative to sort out the collection part of the content of amyloidosis, further flight mass spectrometry of surface-enhanced laser desorption/ionization- time (SELDI TOF MS) to analyze each part of TTR event protein modification type. Results: It was found that SSA patients and healthy volunteers whose serum pH were 8.0- 8.6, pH 4.0-4.6 and pH 5.8-6.8 had a high abundance of protein. Moreover, during pH 6.8 to 5.8, the amyloidosis content of SSA patient group had significantly higher pH than the control group. The TTR N-terminal amino acid modified groups: Phosphoryl, Hydroxyl, O - GlcNac were negative. Conclusion: The reduction of TTR event N-terminal amino acid modified protein was found in SSA patients and Phosphoryl (Phosphoryl), Hydroxyl (Hydroxyl), glucosamine (O - GlcNac) may be associated with the formation of amyloid protein.