The specificity of some pig and human pepsins towards synthetic peptide substrates.
1. The peptidase activities of pig pepsins A and C and human pepsin and gastricsin were compared. 2. The peptides studied had the general formula A Leu Val-His-B. Hydrolysis at 37 degrees C and pH 2.07 occurred at the amino side of the leucine residue for all the enzymes and all the peptides. 3. When A was Ac-Ala the peptides were hydrolysed under these conditions slowly by pig pepsin C only. 4. Pig pepsin A and human pepsin were unable to hydrolyse the tyrosine-containing peptides under the conditions tested. Gastricsin (human pepsin C) had about one-third of the activity of pig pepsin C with these substrates. 5. The increase in the rate of hydrolysis caused by the extension of the chain by a single alanine residue was most marked for pig pepsin A and human pepsin.
D000818:Animals; D006801:Humans; D006868:Hydrolysis; D007700:Kinetics; D010434:Pepsin A / Q000378:metabolism*; D010455:Peptides / Q000378:metabolism*; D013379:Substrate Specificity; D013552:Swine
D010455:Peptides; D010434:Pepsin A