The function of t-PA is to cleave a particular peptide bond in plasminogen, forming plasmin (which is itself a serine protease ).
Serine Protease In the diagram above a small peptide is shown being cleaved, while the usual substrate would be a larger polypeptide.
The serine protease factor B is central in the alternative pathway of activation.
Incorporating CpTI into assays using fluorogenic substrates we were able to show that the serine PI inhibited the activity of the refolded proteinases.
We are studying the structural biology of members of the serpin family of serine proteinase inhibitors using X-ray crystallography.