Pancreatin, protein hydrolysis

Pancreatic and malt amylases gradually lose their activity in the aqueous dispersions in which they act. As above noted, there is good evidence that this is due to a destructive hydrolysis of the enzyme. The destructive action of water upon enzyme is less pronounced in the presence of substrate, probably because the combination of enzyme with substrate serves to some extent to protect the enzyme from hydrolysis. It is less rapid in solutions of commercial pancreatin and in water extracts of malt than it is in solutions of purified pancreatic and malt amylases, doubtless because of the presence in the former of substances which are products of protein hydrolysis (proteoses, peptones, polypeptids, amino acids) and whose presence therefore tends to retard further protein hydrolysis and thus to protect the enzyme protein from hydrolytic destruction, or at least to diminish the rate at which such deterioration of the enzyme occurs. 

Hydrolytic enzymes Pancreatin Hydrolysis of starch (amylase), fat (lipase), and protein (protease) Porcine pancreas Digestive aid... 

Tower et al. (1962) have employed enzymatic hydrolysis with pancreatin preparations for liberation of glutamine and asparagine from proteins. Under the conditions employed, proteins were not hydrolyzed to an extent of more than 50-80 %, but after correcting for incomplete hydrolysis, yields of the two amides were in excellent agreement with theoretical values. 

To start the second step of the hydrolysis, 15 ml of pancreatin solution (5 mg/ml, hog pancreas 5X) in phosphate buffer was introduced in the bag and mixed with the products of pectic digestion. Pancreatic hydrolysis products then were continuously collected as they were dialyzed for various periods of up to 24 hours. The amount of nitrogen released was determined by an Auto Analyzer (using the method no 329-74 W/B of Technicon, Tarrytown, N.Y.). Samples of dialysate and undigested protein fractions were hydrolyzed for 24 h in 6 N HCl at lOO C. Amino acid content was evaluated by high performance liquid chromatography (Vachon al., 1982). 

The B.P. method of assay for trypsin in pancreatin is based on the fact that amino-acids are formed by hydrolysis of protein by trypsin formaldehyde forms methylene compounds with the amino-groups, the carbonyl groups being free for titration with alkali. This method, due to Evers and Smith, uses purified casein adjusted to pH 7 before the addition of formaldehyde and then titration to pH 8 7. A slightly modified method is the following ... 

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