The trypsin molecule has two domains: one is related to the enzyme active site and the tryptophan residues; the other is related to the 8-anilinonaphthalene-1-sulfonate binding.

An experimental approach using SDS-PAGE, in-gel trypsin digestion and proteomic analysis identified five endosomal proteins.Trypsin cleavage of the high-risk HPV-16 E5 protein (16E5) generates a unique four-amino acid C-terminal peptide that serves as a marker for E5 expression in transfected cells and epithelial cell lines containing integrated and episomal HPV-16 DNA.