Nedd8 Conjugation Kit is designed for assaying the conjugation of Nedd8 to protein substrates in vitro. In a protein neddylation reaction, Nedd8 is first activated by the Nedd8 activating enzyme APPBP1/UBA3 (E1) in an ATP hydrolysis-dependent manner; activated Nedd8 is then transferred to the Nedd8 conjugating enzyme Ube2M (UbcH12) (E2) by formation of a thiolester bond with the catalytic cysteine residue of UbcH12I; Nedd8-charged Ube2M (UbcH12) can mediate protein neddylation in the presence of an appropriate Nedd8 ligase (E3).