图1. E2-泛素结合能力实验(Zhao et al., 2013)
利用原核表达纯化得到的His-E2和His-Ub进行体外泛素化反应, 根据是否能产生对DTT敏感的硫酯键, 判断E2是否具有结合泛素的能力。箭头所指条带即为含有对DTT敏感硫酯键的His-E2-Ub或His-E2-Ubn化合物, 三角形所指是未与Ub结合的His-E2, 星号所指为游离的His-Ub。

Figure 1. E2 ubiquitin conjugation assay (Zhao et al., 2013)
In vitro ubiquitination assay was performed with purified His-E2 and His-Ub protein expressed in bacteria. E2-ubiquitin conjugation was detected by whether the DTT-sensitive thioester linkage can form or not. The arrows indicate the DTT-sensitive thioester linkage, the open triangles indicate bands of E2 protein itself that was not attached to Ub, and asterisks indicate His’s-tagged Ub.