kallikrein

https://doi.org/10.1351/goldbook.13356
Any of a group of enzymes found in the blood and body fluids that acts on certain plasma globulins to produce bradykinins.
Source:
PAC, 2012, 84, 1113. (IUPAC glossary of terms used in immunotoxicology (IUPAC Recommendations 2012)) on page 1198 [Terms] [Paper]