Eliminating the six N ‐terminal amino acids of the caspase 3 large subunit improved production of a biologically active IL2‐Caspase3 chimeric protein

Designing a chimeric protein and developing a procedure for its stable production as a biologically active protein, are key steps in its potential application to clinical trails. IL2‐Caspase3 chimeric protein designed to target activated T lymphocytes was found to be a promising molecule for targeted treatment, however was found to be difficult to produce as a biological active molecule. Thus, we designed a new version of the molecule, IL2‐Caspase3s, in which six amino acids (aa 29–34) from the N ‐terminus of the large subunit of caspase 3 were excluded. Repeated expressions, productions, and partial purifications of the IL2‐Caspase3s yielded reproducible batches with consistent results. We found that IL2‐Caspase3s causes cell death in a specific, dose‐, and time‐dependent manner. Cell death due to IL2‐Caspase3s is caused by apoptosis. This improved and biologically stable IL2‐Caspase3s chimeric protein may be developed in the future for clinical trails as a promising therapy for several pathologies involving activated T‐cells. Moreover, this truncated caspase 3 sequence, lacking the N ‐terminal six amino acids of its large subunit, may be used in other caspase 3‐based chimeric proteins targeted against various human diseases, using the appropriate targeting moiety. © 2012 American Institute of Chemical Engineers Biotechnol. Prog., 2012