Expression and subcellular localization of P9-ZFD protein in patients with myasthenia gravis / 中国医学科学杂志(英文版)

ABSTRACT

<p><b>OBJECTIVE</b>To express and purify the protein coded by the TRAF-type zinc finger domain of myasthenia gravis (MG)-related gene P9 (P9-ZFD) and to prepare P9-ZFD antiserum for detecting expression and subcellular distribution of P9-ZFD protein in the skeletal muscles of patient with MG.</p><p><b>METHODS</b>The cDNA encoding P9-ZFD was amplified by RT-PCR. The cloned P9-ZFD cDNA was ligated into pET24a, and the P9-ZFD recombinant protein was induced via E. coli. BL21 (DE3) and purified by histidine affinity chromatography. P9-ZFD antiserum was prepared and its titer and specificity were determined by ELISA and Western blot. Expression and subcellular distribution of P9-ZFD protein in the skeletal muscles of MG and control were studied.</p><p><b>RESULTS</b>The molecular weight of purified P9-ZFD protein was about 30 kD. Its purity was more than 95%. Antiserum specific for P9-ZFD was excellent. P9-ZFD protein is fully confined to the cytoplasm membrane of skeletal muscle cell of MG, obvious immunostaining was absent in the A, I, and Z bands of cytoplasm and no immunoreactivity was observed in the skeletal muscle cell of control.</p><p><b>CONCLUSION</b>P9-ZFD protein is expressed as a cytoplasm membrane-bound protein and has obvious distribution difference in the skeletal muscle cells of patient with MG and normal control.</p>