Anti‐M9 antibodies in sera from patients with primary biliary cirrhosis recognize an epitope of glycogen phosphorylase
Anti‐M9 antibodies in sera from patients with primary biliary cirrhosis recognize an epitope of glycogen phosphorylase
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原发性胆汁性肝硬化患者血清中的抗 M9 抗体可识别糖原磷酸化酶的表位
DOI：
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发表时间：
1990
影响因子：
4.6
通讯作者：
P. Berg
中科院分区：
文献类型：
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作者：
R. Klein;P. Berg
先前发现原发性胆汁性肝硬化（PBC）患者血清中的Anli-M9抗体识别98和59 kD的两个抗原决定簇，使用来自大鼠肝脏线粒体的纯化抗原组分进行Western印迹。在这里，我们表明，这些抗体是针对酶糖原磷酸化酶的表位。通过蛋白质印迹法，获得了98 kD的决定簇，测试抗M9阳性血清对骨骼肌磷酸化酶的作用，纤溶酶处理后，降解产物出现在59 kD。如吸收研究所示，这两个决定簇与M9特异性决定簇98和59 kD相同。当这些抗体在免疫印迹后从M9抗原的98和59 kD决定簇洗脱时。他们再次在纤溶酶处理的磷酸化酶上识别出相同的表位。此外，在纯化的M9组分中也可以证明磷酸化酶活性，并且抗M9阳性/抗M2阴性血清而非抗M9阴性/抗M2阳性血清可以显示刺激磷酸化酶活性。通过ELISA检测1189例不同肝脏和非肝脏疾病患者的血清中M9和骨骼肌磷酸化酶的活性。磷酸化酶阳性率为20%，M9组分仅为2%。这些数据表明，来自骨骼肌的市售磷酸化酶不能推荐作为M9来源。它可能仍然含有非PBC特异性表位，这些表位可能被天然存在的针对这种高度保守蛋白的抗体识别。
Anli‐M9 antibodies in sera from patients with primary biliary cirrhosis (PBC) were previously found to recognize two antigenic determinants at 98 and 59 kD, using a purified antigen fraction derived from rat liver mitochondria in the Western blot. Here we show that these antibodies are directed against an epitope of the enzyme glycogen phosphorylase. By Western blotting, a determinant at 98 kD was obtained testing anti‐M9 positive sera against phosphorylase from skeletal muscle, and after plasmin treatment a degradation product appeared at 59 kD. Both determinants were identical to the M9‐specific determinants 98 and 59 kD as shown by absorption studies. When these antibodies were eluted from the 98 and 59 kD determinants of the M9 antigen after immunoblotting. they again recognized the same epitopes on plasmin‐treated phosphorylase. Furthermore, phosphorylase enzyme activity could be also demonstrated in the purified M9 fraction, and anti‐M9‐positive/anti‐M2‐negative but not anti‐M9‐negative/anti‐M2‐positive sera could be shown to stimulate phosphorylase activity. Testing sera from 1189 patients with different hepatic and non‐hepatic disorders against M9 and phosphorylase from skeletal muscle by ELISA. 20% were positive with phosphorylase and only 2% with the M9 fraction. These data indicate that the commercially available phosphorylase from skeletal muscle cannot be recommended as M9 source. It may still contain non‐PBC‐specific epitopes which are probably recognized by naturally occurring antibodies directed against this highly conserved protein.