Binding of Sudan II and Sudan IV to bovine serum albumin: Comparison studies

► The bindings of Sudan II and Sudan IV to bovine serum albumin (BSA) were assessed. ►The two dyes mainly bind BSA at the hydrophobic pocket and via Van der Waals forces. ► These bindings cause alterations in the secondary and tertiary structure of protein. ► Compared with Sudan II, damages to BSA occur more obviously for Sudan IV binding.