The product is a recombinant analog of fibrolase. Fibrolase is a zinc-containing metalloproteinase isolated from the venom of the southern copperhead snake (Agkistrodon contortrix contortrix). It is a small protein that contains 203 residues (Randolph et al. 1992). Alfimeprase https://www.creativebiomart.net/therapeutic-proteins/p/203/recombinant-analog-of-fibrolase/