Table 2.

Pancreatic proteases in infants

Enzyme	Specificity [72]	Activity in infants
Trypsin	Endopeptidase, cleaves bonds at basic amino acids - lysine and arginine	In newborns (at birth and 30 days) 90% to 100% of activity in children (>2 years) after pancreozymin-secretin stimulation [74]. At birth 8% and at 1 month 25 % of activity in children (9 months to 13 years) [73].
Chymotrypsin	Endopeptidase, cleaves bonds at aromatic amino acids - phenylalanine, tyrosine, tryptophan	In newborns (at birth and 30 days) 50% to 60% of activity in children (>2 years) [74].
Elastase	Endopeptidase, cleaves bonds at small amino acids - alanine, glycine, serine	Low activity in infancy, develops during the first 2 years of life [75].
Carboxypeptidases	Exopeptidase, carboxypeptidase A cleaves C-terminal residues with aromatic or aliphatic side chains, carboxypeptidase B cleaves C-terminal residues with basic side chains.	In newborns (at birth and 30 days) 10% to 25% of carboxypeptidase B activity in children (>2 years) [74].