THE MAJOR DOG PANCREAS PROTEIN RECOGNIZED BY AN ANTISERUM TO DOG PROSTATE KALLIKREIN IS THE ANIONIC TRYPSIN

1. On the basis of its immunoreactivity with a polyclonal antiserum to dog prostate kallikrein in Western blot experiments, a 30 kDa protein was purified from the pancreas of the dog using ion-exchange and gel filtration chromatography. 2. That protein was identified as the anion ic trypsin by its NH2-terminal amino acid sequence. 3. The immunoreact ion occurred despite an overall amino acid homology which was limited to 39% between the prostate kallikrein and anionic trypsin. 4. Otherwi se, the anti-prostatic kallikrein antiserum was rather specific since it did not react with dog cationic trypsin, dog renal kallikrein and h uman prostate specific antigen.