重症肌无力患者骨骼肌25000蛋白含量分析

Analysis of 25 kD protein content of skeletal muscles from the patients with myasthenia gravis

目的 探讨重症肌无力 (MG)患者骨骼肌 2 5 0 0 0蛋白质的减少是否具有特异性。方法用Guba Straubsolution (myosin提取液 )提取 2 1例正常 (骨折对照者 )肌肉 ,18例MG患者肌肉及 2 0例其他神经肌病患者肌肉的蛋白 ,用SDS 聚丙烯酰胺凝胶电泳方法分析蛋白成分 ,以伴刀豆凝集素 /辣根过氧化物酶 (ConA/HRP)联合反应检测糖蛋白。结果 SDS PAGE电泳图谱显示 ,相对分子质量约2 5 0 0 0的蛋白质谱带浓度在MG肌肉中明显低于正常对照肌肉和其他神经肌病肌肉。正常肌肉该蛋白谱带密度为 3 4± 1 5 ,MG肌肉为 1 6± 0 7,其他神经肌病肌肉为 3 7± 1 5 ;正常与其他神经肌病肌肉中 2 5 0 0 0蛋白质水平几乎没有差异 (P =0 899) ,但两者该蛋白质水平与MG肌肉差异非常明显(P <0 0 0 1)。电泳分析亦表明 2 5 0 0 0蛋白质与乙酰胆碱受体分子无关。糖蛋白检测揭示相对分子质量 2 5 0 0 0蛋白质为糖蛋白。结论 (1)MG肌肉中 2 5 0 0 0蛋白质水平特异性地低于正常肌肉和其他神经肌病肌肉 ,提示该蛋白可能与MG发病或发展有关 ;(2 ) 2 5 0 0 0蛋白质是一种糖蛋白 ,但不是乙酰胆碱受体蛋白。

Objective To explore whether the 25 kD protein component was a specific decrease in skeletal muscles of the patients with myasthenia gravis (MG). Methods The muscular proteins were extracted from 21 cases of normal objects,18 cases of patients with myasthenia gravis and 20 cases of patients with other neuro-muscular disorders with Guba-Straub solution. The components of protein were analysed by SDS-PAGE in double blind. Components of glycoprotein were detected by using the ConA/HRP.Results SDS-PAGE patterns showed that the concentration of protein bands with mass of about 25 kD in the MG muscles was much lower than that of muscles in both normal and other neuro-musclular disorders. The value of density for 25 kD protein bands was 1.6±0.7 in the MG muscles,but was 3.4±1.5 and 3.7±1.5 in the muscles of normal and other neuro-musclular disorders,respectively. In addition,25 kD protein was found as a glycoprotein,but it was different from AChR in the molecular weight.Conclusion (1) It was suggested that the pathogeny or developing of MG could be associated with 25 kD protein of the skeletal muscle because of its specific decrease. (2) 25 kD protein was a glycoprotein which was unassociated with the AChR molecule.