Introduction The Small Ubiquitin MOdifier (SUMO) gene fusion system allows for the efficient removal of SUMO tags. The CoolCutter™ SUMO Protease product is a mixture of recombinant human and mouse SUMO proteases which delivers superior SUMO cleavage activity with both the native sumoylated proteins and the SUMO tag in recombinant SUMO fusion proteins. The CoolCutter™ enzyme recognizes the tertiary structure of SUMO rather than an amino acid sequence for a clean release of the desired peptides. A high activity in a wide range of pH, salt and detergent concentrations makes CoolCutter™ SUMO protease highly suitable for recombinant protein expression and purification. CoolCutter™ SUMO protease can cleave any protein that is fused to the C-terminus of SUMO except for fused proteins beginning with proline.Cleavage efficiency of CoolCutter SUMO Protease is low for those SUMO-fused proteins that begin with luecine, lysine or valine. CoolCutter™ SUMO Protease is ideal for use with OmicsLink™ Expression-Ready Clones, particularly the bacterial pReceiver-B12 and pReceiver-B13 vectors.