Meyer D I, Dobberstein B
J Cell Biol. 1980 Nov;87(2 Pt 1):503-8. doi: 10.1083/jcb.87.2.503.
When rough microsomes are subjected to limited proteolysis and high salt, a soluble fraction can be separated from the membrane. Neither fraction alone is capable of vectorially translocating nascent peptides. When the soluble extract is recombined with the residual membrane fraction, translocating activity is restored. Standard biochemical techniques were used to identify and characterize the active component derived by treating rough microsomes with elastase and high salt. The active factor is a peptide fragment with an apparent molecular weight of 60,000. It represents the cytoplasmic domain of a larger membrane protein. The fragment is basic and has at least one accessible sulfhydryl group. These characteristics facilitated its purification and identification as a membrane component required for translocation of nascent peptides across microsomal membranes.
当粗面微粒体受到有限的蛋白酶解作用和高盐处理时，可从膜中分离出一个可溶性部分。单独的这两个部分都不能进行新生肽的向量转运。当可溶性提取物与残留的膜部分重新组合时，转运活性得以恢复。使用标准生化技术来鉴定和表征通过用弹性蛋白酶和高盐处理粗面微粒体而衍生出的活性成分。该活性因子是一个表观分子量为60,000的肽片段。它代表一种较大膜蛋白的胞质结构域。该片段呈碱性，并且至少有一个可及的巯基。这些特性有助于其纯化，并将其鉴定为新生肽跨微粒体膜转运所需的一种膜成分。
