Nouvelles recherches sur le chymotrypsinogène B evaluation quantitative dans le pancréas de boeuf et essai d'identification chez le porc

In this work, bovine chymotrypsinogen B has been quantitatively determined and a first attempt has been made towards the identification of a chymotrypsinogen B in porcine pancreas.

The quantitative technique used for bovine chymotrypsinogen B involves acid denaturation of procarboxypeptidase A, separation of anionic from cationic proteins on CM-cellulose at pH 6.0 and determination of the activity of both fractions against acetyl-l-tyrosine ethylester after tryptic activation. By using the specific activity of the pure precursors, the weight ratio chymotrypsinogen A/chymotrypsinogen B is finally calculated. This ratio is shown to be about 4 in bovine pancreas and pancreatic juice.

The anionic proteins of porcine pancreas and pancreatic juice delay, as in the case of bovine pancreas a strong activity against acetyl-l-tyrosine ethylester. This kind of activity is not given by porcine procarboxypeptidase A which, in contrast with its bovine analog, does not hydrolyze acetyl-l-tyrosine ethylester after tryptic treatment, but my several other anionic proteins which can be partly separated on DEAE-cellulose at pH 8.0. It is not yet known whether or not one of these proteins is actually a chymotrypsinogen B.