This biotinylated peptide serves as a negative control and contains a scrambled version of the consensus motif sequence (SP-300). It will not be conjugated to SUMO-1, SUMO-2 or SUMO-3 proteins in the presence of the E1 activating (SAE1/SAE2) and UbcH9 conjugating enzymes. The biotin group allows for sensitive and convenient detection using avidin-linked reagents.

SUMO modification of proteins occurs on lysine residues generally found within a short consensus sequence containing the ψΚXE motif. This motif consists of ψ which represents a large hydrophobic amino acid (isoleucine, leucine or valine), K is the lysine that becomes modified, X is any residue and E is glutamic acid. The glutamic acid is the most highly conserved position other than the lysine.