Noun
isopeptide (plural isopeptides)
(chemistry) A compound of two or more amino acids (a peptide) in which an amide link involves an amino group not in the alpha- position
Most commonly, they create an isopeptide bond between a lysine of the target protein and the C-terminal glycine of ubiquitin. Source: Internet
They can cleave both isopeptide (between ubiquitin and lysine) and peptide bonds (between ubiquitin and the N-terminus ). Source: Internet