[Peptide bond scission of staphylococcal enterotoxin C2 and related factors].

Objective: To investigate the limited digestion of recombinant staphylococcal enterotoxin C2 (SEC2-His)in different conditions.

Methods: The purified recombinant SEC2-His was treated with different reagents and the cleavage of rSEC2 molecule was observed by SDS-PAGE.

Result: The cleavage occurred in positions Cys93-Cys110 of the disulfide loop. Complete auto-cleavage of recombinant SEC2 was observed in solution at 37degrees within 24 hrs, and that was accelerated under alkaline conditions. The auto-cleavage of the recombinant protein was inhibited in the presence of beta-ME (2%), PMSF (5-10 mmol/L), imidazole (1 mol/L) or crude E.coli lysate. Non-specific degradation of recombinant SEC2 was promoted with the increasing of the concentration of H(2)O(2).

Conclusion: The recombinant SEC2-His is broken down in special site of protein, which may be associated with the protein structure.