Does pepsin digest plant protein?
Yes, pepsin does digest plant proteins also. Pepsin is a protein and its job is to cut other proteins (also known as polypeptides) into smaller pieces. Proteins are made of amino acids and there are 20 amino acids found in proteins. Pepsin cuts the bond between two amino acids to break the protein into smaller pieces. When pepsin encounters a tryptophan (Trp), tyrosine (Tyr), and/or phenylalanine (Phe), it cuts the bond between that amino acid and the one next one, as shown below.


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Proteins from plants contain these amino acids so pepsin can cleave plant proteins.