Saccharomyces cerevisiae-derived Small ubiquitin-like modifier （SUMO, Smt3） is commonly used as a protein fusion domain to facilitate expression and purification of recombinant proteins, and a Saccharomyces cerevisiae-derived SUMO-specific protease（Ulp1） is then used to remove SUMO tag from these proteins in a ‘scarless’ manner. SUMO Protease cleaves in a highly specific manner, recognizing the tertiary structure of the SUMO tag, rather than an amino acid sequence, and hydrolyzes the peptide bond in the x-Gly-Gly-x sequence after the Gly-Gly bond at the C-terminus of the SUMO tag. The SUMO Protease cleavage proteins over wide ranges of temperature （4℃-30℃）, ionic strengths（0-400 mM NaCl） and pH（7.0-9.0）, and easily removed from the cleavage reaction by Immobilized Metal Affinity chromatography （IMAC）.