Ohkuma S, Noguchi H, Amano F, Mizuno D, Yasuda T
J Biochem. 1976 Jun;79(6):1365-76. doi: 10.1093/oxfordjournals.jbchem.a131191.
Apoferritin particles were found in mouse peritoneal macrophages cultured in vitro. They were found as 20S particles in the "ribosomal fraction" of macrophages labeled with L-[14C]glutamic acid. Possibilities that they were breakdown products of ribosomes or of other well-known contaminants of the ribosomal fraction were excluded because they did not incorporate [5-3H]uridine. They were resistant to RNase and were relatively resistant to detergent. The antibody against horse spleen apoferritin precipitated about 70% of the particles in the 20S region, judging by measurement of radioactivity. On in vitro incubation with Fe2+ and suitable oxidizing agents the sedimentation coefficient of 80% of the 20S particles changed to about 60S, which corresponds to that of ferritin. SDS-polyacrylamide gel electrophoresis revealed the presence of subunit structures with the same molecular size as that of mouse liver apoferritin. Under the electron microscope, the particles appeared spherical with a relatively uniform diameter of about 130 A.
在体外培养的小鼠腹腔巨噬细胞中发现了脱铁铁蛋白颗粒。在用L-[14C]谷氨酸标记的巨噬细胞的“核糖体部分”中，它们以20S颗粒的形式被发现。由于它们不掺入[5-3H]尿苷，因此排除了它们是核糖体或核糖体部分其他知名污染物的分解产物的可能性。它们对核糖核酸酶有抗性，并且对去污剂相对有抗性。通过放射性测量判断，抗马脾脱铁铁蛋白的抗体沉淀了20S区域中约70%的颗粒。在与Fe2+和合适的氧化剂进行体外孵育时，80%的20S颗粒的沉降系数变为约60S，这与铁蛋白的沉降系数相对应。SDS-聚丙烯酰胺凝胶电泳显示存在与小鼠肝脏脱铁铁蛋白分子大小相同的亚基结构。在电子显微镜下，这些颗粒呈球形，直径相对均匀，约为130埃。
