Horne Z, Hesketh J
Biochemistry Division, Rowett Research Institute, Bucksburn, Aberdeen, U.K.
Biochem J. 1990 May 15;268(1):231-6. doi: 10.1042/bj2680231.
Ribosome distribution in skeletal-muscle fibres was investigated immunohistochemically by using polyclonal antibodies raised against large-ribosomal-subunit proteins isolated from rat liver. Immunoblot analysis showed the antibodies to recognize five major proteins of the large subunit; these were identified as L4, L6, L7, L15 and L17 by two-dimensional electrophoresis. Immunohistochemistry of frozen rat skeletal-muscle sections showed staining of both the subsarcolemmal and intermyofibrillar cytoplasm. A distinct banding pattern was observed, and when peroxidase and phase-contrast images of the same field were compared by image analysis the anti-ribosome staining was found to correspond to the A-bands. These results suggest that a proportion of muscle ribosomes are present in the myofibrillar cytoplasm in a regular fashion, possibly associated with myosin. Densitometric analysis of the peroxidase immunostaining showed that the ratio of myofibrillar to sub-sarcolemmal ribosomal material was lower in muscle from 51-day-old rats compared with those from 14-day-old animals.
利用针对从大鼠肝脏分离的大核糖体亚基蛋白产生的多克隆抗体，通过免疫组织化学方法研究了核糖体在骨骼肌纤维中的分布。免疫印迹分析表明，这些抗体可识别大核糖体亚基的五种主要蛋白质；通过二维电泳将它们鉴定为L4、L6、L7、L15和L17。对大鼠骨骼肌冷冻切片进行免疫组织化学分析，结果显示肌膜下和肌原纤维间的细胞质均有染色。观察到一种明显的条带模式，通过图像分析比较同一视野的过氧化物酶图像和相差图像，发现抗核糖体染色与A带相对应。这些结果表明，一部分肌肉核糖体以规则的方式存在于肌原纤维细胞质中，可能与肌球蛋白相关。对过氧化物酶免疫染色进行光密度分析表明，与14日龄动物的肌肉相比，51日龄大鼠肌肉中肌原纤维核糖体物质与肌膜下核糖体物质的比例更低。
