Purity: > 90% by SDS - PAGE Format: Liquid. 20mM Tris-HCl buffer (pH8.0) containing 20% glycerol, 1mM DTT, 0.1mM PMSF . ATG4B, also known as cysteine protease ATG4B, is a cysteine protease required for autophagy, which cleaves the C-terminal part of either MAP1LC3, GABARAPL2 or GABARAP, allowing the liberation of form I. A subpopulation of form I is subsequently converted to a smaller form (form II). Form II, with a revealed C-terminal glycine, is considered to be the phosphatidylethanolamine (PE)-conjugated form, and has the capacity for the binding to autophagosomes. Recombinant human ATG4B protein, fused to His-tag at C-terminus, was expressed in E.coli and purified by using conventional chromatography.