https://www.ncbi.nlm.nih.gov/Structure/pdb/6ZFK
6ZFK: Trypsin inhibitor in complex with bovine trypsin
Cationic trypsin4-oxo-N-[(1S)-1-(pyridin-3-yl)ethyl]-4-(thiophen-2-yl)butanamideCALCIUM IONDIMETHYL SULFOXIDESULFATE ION
trypsininhibitorcomplexbovine