Crystal structures and sequence. (A) Indicating the subdivisions of HSA into domains (I-III) and subdomains (A, B). (B) Indicating the subdivisions of BSA into domains (I-III) and subdomains (A, B). (C) Structure aligned between HSA and BSA. (D) Sequence aligned between HSA and BSA. Atomic coordinates were obtained from the PDB (4IW1 and 4OR0). The illustration was made with Discovery Studio (version 4, BIOVIA, USA). The picture was drown according to reference [13]. BSA, bovine serum albumin; HSA, human serum albumin.