What does PTD stand for?

The chimeric protein contains three polypeptidyl fragments: (a) a first polypeptidyl fragment at the N-terminal end of the chimeric protein that contains a protein transduction domain (PTD) or a fragment thereof having HIV Tat PTD activity; (b) a second polypeptidyl fragment at the C-terminal end of the first polypeptidyl fragment that contains a J-domain or a fragment thereof having heat shock protein 70 (Hsp70)-interacting activity; and (c) a third polypeptidyl fragment at the C-terminal end of the second polypeptidyl fragment that contains a target protein or polypeptide.

The company has proprietary versions of protein transduction domains (PTDs), technology that allows intracellular delivery of genetically validated therapeutics in vivo.

To prime the caspase protein for its starring assisted-suicide role, the co-authors genetically engineered it into a transducible protein by replacing the front third of it with a protein transduction domain.