AUTHORS CRYSTALLIZED ACTIVE PROTEASE WITH 10-MER LENGTH PEPTIDE CORRESPONDING TO CA-P2 CLEAVAGE ...AUTHORS CRYSTALLIZED ACTIVE PROTEASE WITH 10-MER LENGTH PEPTIDE CORRESPONDING TO CA-P2 CLEAVAGE SITE. DURING CRYSTALLIZATION, PROTEASE CLEAVED THE 10-MER PEPTIDE TO TWO 5-MER PRODUCTS (N-TERMINAL KARVL*AEAMS C-TERMINAL, WHERE * INDICATES SITE OF HYDROLYSIS). INITIALLY N-TERMINAL PRODUCT IS MODELED IN THE STRUCTURE AS K1-A2-R3-V4-L5*. THE C-TERMINAL PRODUCT THAT SHOULD HAVE BEEN THEORETICALLY PRESENT NEXT TO N-TERMINAL PRODUCT IN THE PROTEASE ACTIVE SITE MAY HAVE PROBABLY DIFFUSED AWAY POST CLEAVAGE AND (THE DENSITY FOR IT) IS ABSENT IN THE CRYSTAL STRUCTURE. WHAT AUTHORS OBSERVED IS A PARTIAL DENSITY FOR ANOTHER N-TERMINAL PRODUCT FRAGMENT IN ITS PLACE. THIS IS BECAUSE THE CRYSTALLIZED DIMER IS NOT UNIQUELY ORIENTED IN THE CRYSTAL LATTICE. POSSIBLY DUE TO THE AVERAGING OF ELECTRON DENSITY OF ANOTHER PROTEASE DIMER WITH N-TERMINAL PRODUCT THAT IS IN THE OPPOSITE ORIENTATION AS THE FIRST LEADS TO THE OVERALL IMPRESSION OF TWO, SEPARATE N-TERMINAL PRODUCTS BEING PRESENT IN THE ACTIVE SITE OF THE CRYSTALLIZED PROTEASE DIMER. THEREFORE, ARVL*LVR IS MODELELD IN ACTIVE SITE WHICH IS NOTHING BUT TWO n-TERMINAL PEPTIDES IN OPPOSITE DIRECTIONS.