Prodouz K N, Moroff G
J Lab Clin Med. 1985 May;105(5):560-7.
The platelet cytoskeleton is a major determinant of platelet morphology and function. Changes in the protein composition of the cytoskeleton were studied during storage of platelets at 20 degrees to 24 degrees C under blood banking conditions. Cytoskeletons were prepared by extraction of washed platelets with the detergent Triton X-100 and then analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. In addition to the three major proteins visible with Coomassie blue staining--actin, myosin, and actin-binding protein--silver staining revealed other proteins associated with the cytoskeletons of freshly collected and stored platelets. The resting platelet cytoskeleton contained 8% to 10% of the total platelet protein and approximately 50% of the total actin. During storage of platelet concentrates for up to five days in the PL 732 container, proteins of 50,000 to 55,000 and 90,000 mol wt were increasingly incorporated into the Triton-insoluble fraction, whereas the amounts of cytoskeleton-associated actin-binding protein, myosin, and actin were maintained at levels present in fresh platelets. Storage of platelets under conditions that allowed the reduction of platelet concentration pH to nearly 6.0 resulted in a marked decrease in the amounts of the major proteins of the cytoskeleton. The loss of specific proteins from platelets stored for extended periods with reduced pH, accompanied by the appearance of lower molecular weight proteins in the cytoskeleton, suggests that extensive proteolysis may occur under certain storage conditions. These data show that the conditions employed for storage of platelet concentrates influence the protein composition of the cytoskeleton and the total protein content of the platelet.
血小板细胞骨架是血小板形态和功能的主要决定因素。在血库条件下，于20℃至24℃储存血小板期间，研究了细胞骨架蛋白质组成的变化。通过用去污剂曲拉通X - 100提取洗涤后的血小板来制备细胞骨架，然后通过十二烷基硫酸钠 - 聚丙烯酰胺凝胶电泳进行分析。除了考马斯亮蓝染色可见的三种主要蛋白质——肌动蛋白、肌球蛋白和肌动蛋白结合蛋白——银染色还揭示了与新鲜采集和储存血小板的细胞骨架相关的其他蛋白质。静息血小板细胞骨架占血小板总蛋白的8%至10%，约占总肌动蛋白的50%。在PL 732容器中储存血小板浓缩物长达五天期间，分子量为50,000至55,000和90,000的蛋白质越来越多地掺入曲拉通不溶性部分，而与细胞骨架相关的肌动蛋白结合蛋白、肌球蛋白和肌动蛋白的量保持在新鲜血小板中的水平。在允许血小板浓缩物pH值降至近6.0的条件下储存血小板，导致细胞骨架主要蛋白质的量显著减少。长时间在低pH值下储存的血小板中特定蛋白质的丢失，伴随着细胞骨架中低分子量蛋白质的出现，表明在某些储存条件下可能发生广泛的蛋白水解。这些数据表明，用于储存血小板浓缩物的条件会影响细胞骨架的蛋白质组成和血小板的总蛋白含量。
