Human serum albumin (HSA) has been chemically modified with 1,2-cyclohexanedione and N-acetylimidazole under nondenaturing conditions. Derivatives, in which 10 arginine residues (1,2-dihydroxycyclohex-1,2-ylene (DHCH)-HSA), 56 to 57 lysine and 5 tyrosine residues (acetyl-HSA), or 56 to 57 lysine residues alone (O-deacetyl-HSA) are modified, have been isolated. Their conformation has been tested...