[Hydrolysis of the isopeptide epsilon-(gamma-glutamyl)-lysine by destabilase from the medicinal leech Hirudo medicinalis].

Using amino acid analysis, the ability of destabilize to hydrolyze the epsilon-(gamma-Glu)-Lys isopeptide bond was demonstrated. Incubation of the epsilon-(gamma-Glu)-Lys isopeptide with the enzyme was accompanied by a decrease of the amount of the isopeptide and an increase of equimolar amounts of lysine and glutamic acid. Complete hydrolysis of the isopeptide was observed after 96 hour incubation with destabilize. It was supposed that the isopeptide is a less specific substrate for destabilize compared to L-gamma-Glu-pNA.