To find a reasonable way to prepare the designed CPP32 inhibitors. Method Ugifour-component condensation reaction was used to synthesize peptide mimic CPP32 inhibitors; ResultsA key isocyanide component (aspartate-derived isocyanide 3) and one of the designed CPP32inhibitors 4 (as a template) were synthesized; Conclusion The CPP32 inhibitor 4 was synthesized bythe newly developed procedure, which is an Ugi four-component condensation reaction based onaspartate-derived isocyanide 3. This method can be used to build up the CPP32 inhibitor library.
Exposure of naive murine CD4 + T lymphocytes to superantigen such as staphylococcal enterotoxin B (SEB) induces a strong proliferative response. Prolonged exposure or subsequent restimulation of the responding T cell population with SEB leads to the apoptotic events of activation-induced cell death (AICD). The signaling mechanism responsible for the AICD is a target of intensive investigation. However, the precise downstream signaling pathways of SEB-induced AICD remains unclear. Our results here show that the sequential activation of caspase-1/ICE-like and caspase-3/CPP32-like cysteine proteases probably plays a role in the signaling transduction of SEB-induced AICD, but caspase-3/CPP32-like proteases activation does not depend on caspase-1-like proteases activation. Herbimycin A, a specific inhibitor of protein tyrosine kinases, inhibit caspase-3/CPP32-like cysteine proteases activation. However, it does not prevent DNA fragmentation of CD4 + T cells apoptosis induced by SEB. These results indicate that protein tyrosine kinases pathway is probably involved in the signaling transduction of CD4 + T cells apoptosis induced by SEB and “crosstalks” with the pathway of caspase-3/CPP32-like proteases activation.
