Ruud E, Kindberg G M, Blomhoff H K, Godal T, Berg T
Immunology Laboratory, Institute for Cancer Research, Oslo, Norway.
J Immunol. 1988 Nov 1;141(9):2951-8.
The surface IgM-mediated endocytosis and intracellular transport of an anti-F(c mu)5 mAb was studied by using subcellular fractionation in sucrose gradients. The results of such experiments showed that antibody was initially endocytosed in vesicles of low density, and later transferred to a presumably lysosomal compartment of higher density. SDS-PAGE analysis of gradient fractions showed that high Mr degradation fragments of the endocytosed antibody were formed in the low density vesicles before terminal degradation could be recorded. The partial degradation of the antibody was not blocked by low temperature or enzyme inhibitors, such as leupeptin and benzyloxycarbonyl-phenylalanylalanine-diazomyethyl-ketone, all of which severely retarded terminal degradation. The data also suggested that the recycling of partially degraded antibody to the cell surface employed a pool of such low density prelysosomal vesicles.
通过蔗糖梯度亚细胞分级分离法研究了抗 F(cμ)5 单克隆抗体的表面 IgM 介导的内吞作用和细胞内运输。此类实验结果表明，抗体最初在低密度囊泡中被内吞，随后转移至密度更高的可能是溶酶体的区室。梯度级分的 SDS-PAGE 分析表明，在内吞抗体的高分子量降解片段在可记录到最终降解之前就在低密度囊泡中形成。抗体的部分降解不受低温或酶抑制剂（如亮抑酶肽和苄氧羰基 - 苯丙氨酰丙氨酸 - 重氮甲基酮）的阻断，所有这些抑制剂都会严重阻碍最终降解。数据还表明，部分降解的抗体向细胞表面的再循环利用了这样一批低密度的溶酶体前囊泡。
