| Autor: |
Gil-Parrado, Shirley, Assfalg-Machleidt, Irmgard, Fiorino, Ferdinando, Deluca, Dominga, Pfeiler, Dietmar, Schaschke, Norbert, Moroder, Luis, Machleidt, Werner |
| Předmět: |
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| Zdroj: |
Biological Chemistry; Mar2003, Vol. 384 Issue 3, p395-402, 8p, 1 Diagram, 1 Chart, 2 Graphs |
| Abstrakt: |
The ubiquitous calpains, µ- and m-calpain, have been implicated in essential physiological processes and various pathologies. Cell-permeable specific inhibitors are important tools to elucidate the roles of calpains in cultivated cells and animal models. The synthetic N-acetylated 27-mer peptide derived from exon B of the inhibitory domain 1 of human calpastatin (CP1B) is unique as a potent and highly selective reversible calpain inhibitor, but is poorly cell-permeant. By addition of N-terminal cysteine residues we have generated a disulfide-conjugated CP1B with the cell-penetrating 16-mer peptide penetratin derived from the third helix of the Antennapedia homeodomain protein. The inhibitory potency and selectivity of CP1B for calpain versus cathepsin B and L, caspase 3 and the proteasome was not affected by the conjugation with penetratin. The conjugate was shown to efficiently penetrate into living LCLC 103H cells, since it prevents ionomycin-induced calpain activation at 200-fold lower concentration than the non-conjugated inhibitor and is able to reduce cal-pain-triggered apoptosis of these cells. Penetratin-conjugated CP1B seems to be a promising alternative to the widely used cell-permeable peptide aldehydes (e.g. calpain inhibitor I) which inhibit the lysosomal cathepsins and partially the proteasome as well or even better than the calpains. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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