Grandori R, Vai M, Di Renzo M F, Alberghina L, Popolo L
Dept. of General Physiology and Biochemistry, University of Milano, Italy.
Biochem Biophys Res Commun. 1989 Apr 28;160(2):887-96. doi: 10.1016/0006-291x(89)92518-7.
Immunoblot analysis with anti-phosphotyrosine antibodies of total extracts from exponentially growing yeast cells reveals a unique cross-reactive polypeptide of about 75 Kd (p75). The specificity of the immunodecorations has been checked by experiments of competition with phosphoaminoacids. A common behaviour has been observed for the 75 kd band and the 170 kd band corresponding to the platelet-derived growth factor receptor from Swiss 3T3 cells, which it has been known to be autophosphorylated on tyrosine upon ligand binding and used as a control throughout this work. We have found that p75 is associated to detergent insoluble cytoplasmic matrices. The stability of p75 detection by antibodies following treatments that specifically hydrolyze phosphohistidine and its susceptibility to potato acid phosphatase treatment provide further evidences that the epitope recognized by these antibodies in the yeast p75 polypeptide is indeed phosphotyrosine.
用抗磷酸酪氨酸抗体对指数生长期酵母细胞的总提取物进行免疫印迹分析，发现一条约75千道尔顿（p75）的独特交叉反应性多肽。通过与磷酸氨基酸的竞争实验检查了免疫标记的特异性。已观察到75 kd条带和与来自瑞士3T3细胞的血小板衍生生长因子受体相对应的170 kd条带具有共同行为，已知该受体在配体结合后酪氨酸会发生自身磷酸化，并在整个这项工作中用作对照。我们发现p75与去污剂不溶性细胞质基质相关。经特异性水解磷酸组氨酸的处理后，抗体检测p75的稳定性及其对马铃薯酸性磷酸酶处理的敏感性提供了进一步证据，表明这些抗体在酵母p75多肽中识别的表位确实是磷酸酪氨酸。
