Robuta

https://www.ncbi.nlm.nih.gov/Structure/pdb/3BTQ 3BTQ: THE CRYSTAL STRUCTURES OF THE COMPLEXES BETWEEN BOVINE BETA-TRYPSIN AND TEN P1 VARIANTS OF... PROTEIN (BOVINE PANCREATIC TRYPSIN INHIBITOR)PROTEIN (TRYPSIN)CALCIUM IONSULFATE ION