Practice question

Bovine serum albumin commonly abbreviated BSA sixty six point five kilodalton 585 amino acid residues after cleavage N-terminal signal peptide twenty four amino acids, three homologous domains I II III each divided into two subdomains A B stabilized by total seventeen disulfide bonds forming heart-shaped globular structure approximately eighty by eighty by thirty angstroms with hydrophobic pockets located in subdomains IIA site one also known as warfarin binding site and IIIA site two ibuprofen binding site that transport hydrophobic molecules: long chain fatty acids oleic acid palmitic acid at five to seven sites increasing solubility ten thousand fold, bilirubin product heme catabolism preventing kernicterus, thyroxine T4 thyroid hormone, steroid hormones cortisol, metal ions copper nickel via N-terminal metal binding ATCUN motif Asp Ala His, drugs warfarin ibuprofen altering pharmacokinetics. Buffering function due imidazole side chains sixteen histidine residues pKa around six providing 20 percent of plasma buffering capacity at neutral pH scavenging protons. Antioxidant capacity via free thiol at cysteine thirty four 0.