Ciment G, Ressler A, Letourneau P C, Weston J A
J Cell Biol. 1986 Jan;102(1):246-51. doi: 10.1083/jcb.102.1.246.
The antigen recognized by the E/C8-monoclonal antibody is expressed in various avian embryonic cell types known also to express neurofilament (NF) immunoreactivity. To determine whether the E/C8-antigen corresponds to any of the known NF components, we compared their subcellular locations, immunocross-reactivities, and electrophoretic behaviors. We found that the E/C8-antibody binds to NF bundles in electron microscope preparations of neurons, but does not correspond to any of the known NF proteins by immunological or electrophoretic criteria. Immunoadsorption with the monoclonal antibody resulted in co-purification of a 73,000-D protein with one of the known NF proteins in homogenates from 20-d embryonic chick brains, but with vimentin intermediate filament protein in similarly prepared homogenates from 4-d embryonic chicks. We suggest that the E/C8-antigen is an intermediate filament-associated protein that binds to different filament types at different stages of development. We have named it NAPA-73, an acronym for neurofilament-associated protein, avian-specific, 73,000 D, on the basis of its binding specificity in mature neurons.
E/C8单克隆抗体识别的抗原在多种禽胚胎细胞类型中表达，这些细胞类型也已知表达神经丝（NF）免疫反应性。为了确定E/C8抗原是否与任何已知的NF成分相对应，我们比较了它们的亚细胞定位、免疫交叉反应性和电泳行为。我们发现，E/C8抗体在神经元的电子显微镜制剂中与NF束结合，但根据免疫学或电泳标准，它与任何已知的NF蛋白都不对应。用单克隆抗体进行免疫吸附导致在20日龄胚胎鸡脑匀浆中，一种73,000-D的蛋白与一种已知的NF蛋白共纯化，但在4日龄胚胎鸡同样制备的匀浆中，与波形蛋白中间丝蛋白共纯化。我们认为E/C8抗原是一种中间丝相关蛋白，在发育的不同阶段与不同的丝状体类型结合。基于其在成熟神经元中的结合特异性，我们将其命名为NAPA-73，即神经丝相关蛋白、禽类特异性、73,000 D的首字母缩写。
