Krop-Watorek A, Sedlaczek P, Lisowska E
Mol Immunol. 1983 Jul;20(7):777-85. doi: 10.1016/0161-5890(83)90056-1.
NCA was purified from normal human lung (L-NCA) and from liver metastases of colon adenocarcinoma (T-NCA), L-NCA and T-NCA had different carbohydrate compositions, but showed an immunological identity in double immunodiffusion with the use of anti-CEA and anti-L-NCA sera. In SDS-polyacrylamide gel electrophoresis L-NCA and T-NCA showed similar molecular weights of about 110,000 and 120,000, respectively. However, if the samples were heated for 3 min at 100 degrees C in the presence of 1% SDS before electrophoresis, their apparent mol. wt decreased to about 50,000, suggesting the dissociation of NCA molecules into subunits. The dissociation of NCA was independent of the presence of mercaptoethanol and did not destroy the ability of NCA to precipitate with anti-CEA and anti-NCA sera. Besides NCA (and CEA in tumor tissue), the presence of a lower molecular weight cross-reacting antigen was observed in lung and tumour. Double immunodiffusion showed that this additional antigen was not a dissociated form of NCA.
NCA从正常人肺组织（L-NCA）和结肠腺癌肝转移灶（T-NCA）中纯化得到，L-NCA和T-NCA具有不同的碳水化合物组成，但在使用抗CEA和抗L-NCA血清的双向免疫扩散中显示出免疫同一性。在SDS-聚丙烯酰胺凝胶电泳中，L-NCA和T-NCA分别显示出约110,000和120,000的相似分子量。然而，如果样品在电泳前于100℃在1% SDS存在下加热3分钟，其表观分子量降至约50,000，表明NCA分子解离成亚基。NCA的解离与巯基乙醇的存在无关，并且不破坏NCA与抗CEA和抗NCA血清沉淀的能力。除了NCA（以及肿瘤组织中的CEA），在肺和肿瘤中还观察到低分子量交叉反应抗原的存在。双向免疫扩散表明这种额外的抗原不是NCA的解离形式。
