Finbow M E, Buultjens T E, John S, Kam E, Meagher L, Pitts J D
Ciba Found Symp. 1987;125:92-107. doi: 10.1002/9780470513408.ch6.
The proteins in various gap junctional preparations from rodent liver have been analysed by two-dimensional peptide mapping and immunoblotting. Only the protein of relative molecular mass (Mr) 16,000 (16K) is found in all gap junctional isolates, and it is unrelated to the 27K protein. The absence of the 27K protein and any of its fragments from trypsin-treated preparations suggests that this protein does not directly contribute to gap junctional structure. Peptide mapping and immunoblotting of the 16K proteins isolated from various tissues and species and of the arthropod 18K protein present in gap junctional preparations from Nephrops norvegicus show that these proteins constitute a family of related junctional proteins. A site-specific antiserum raised against the N-terminal octapeptide of the 16K protein from mouse liver cross-reacts with all 16K and 18K forms of the junctional protein so far tested, suggesting that this particular antigenic determinant is highly conserved. Immuno-localization studies show that the N-terminus is most likely located on the cytoplasmic aspect of the junction and is available to Pronase digestion.
已通过二维肽图谱分析和免疫印迹法对来自啮齿动物肝脏的各种间隙连接制剂中的蛋白质进行了分析。在所有间隙连接分离物中仅发现相对分子质量（Mr）为16,000（16K）的蛋白质，并且它与27K蛋白质无关。经胰蛋白酶处理的制剂中不存在27K蛋白质及其任何片段，这表明该蛋白质不直接参与间隙连接结构的形成。对从各种组织和物种中分离出的16K蛋白质以及存在于挪威龙虾间隙连接制剂中的节肢动物18K蛋白质进行肽图谱分析和免疫印迹，结果表明这些蛋白质构成了一个相关连接蛋白家族。针对小鼠肝脏16K蛋白质N端八肽产生的位点特异性抗血清与迄今为止测试的所有16K和18K形式的连接蛋白发生交叉反应，这表明该特定抗原决定簇高度保守。免疫定位研究表明，N端最有可能位于连接的细胞质一侧，并且可被链霉蛋白酶消化。
