Procarboxypeptidase A is the zymogen of an exopeptidase, carboxypeptidase A, which liberates from peptides and proteins carboxyl-terminal amino acids whose side chains conform to the specificity requirements of this enzyme.1 The active enzyme can be isolated from activated bovine pancreatic juice or from drippings of fresh pancreas glands by a procedure originally described by Anson ;2 alternatively, the enzyme can be isolated from acetone powder of unactivated beef pancreas glands by the procedure of Allan,3 which is now undergoing further modifications and refinements. Carboxypeptidase A is a metalloenzyme which is inhibited by 1,10 phenanthroline and other metal chelating agents, zinc being the metal which is functionally and structurally intrinsic to the native enzymes. 4 5 Several molecular parameters pertaining to size, charge properties, and amino acid composition of the enzyme are well established, ' but the detailed chemical structure of this enzyme remains to be elucidated. Experiments to this end are part of a group program now in progress in this laboratory and in the laboratories of B. L. Vallee, Harvard Medical School. Procarboxypeptidase A, the inactive precursor of this enzyme, can be found as such in bovine pancreatic juice, in zymogen granules,6 and in other subcellular components of the acinar cells of the bovine pancreas, and the metabolic origin
Home-brewed beers and wines from various sources have been analysed by gasliquid chromatography. It was found that the amount of volatiles present especially the fusel oil fraction was invariably higher than in commercially brewed drinks. The consequences and possible dangers of this are discussed.
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