JOSD1, also as known as Josephin-1, has low protease activity towards poly-ubiquitin chains (in vitro). JOSD1 is act as a deubiquitinating enzyme. Recently identified ubiquitin-binding sites in the Josephin domain contribute to ubiquitin chain binding and cleavage. Recombinant human JOSD1 protein, fused to His-tag at Nterminus, was expressed in E.coli and purified by using conventional chromatography techniques.