The displacement of l-tryptophan and dipeptides from bovine albumin in vitro and from human plasma in vivo by antirheumatic drugs

Abstract

Abstract l-Tryptophan occurs in a protein-bound and an unbound form in serum from normal subjects. The amino-acid is displaced from its binding sites in vitro by salicylate, phenylbutazone, indomethacin, prednisolone, chloroquine and gold salts and is virtually absent in serum obtained from patients with rheumatoid arthritis receiving therapy with antirheumatic drugs. Some dipeptides bind to bovine albumin in vitro and are displaced by salicylate. All the drugs displace l-phenylalanyl-l-phenylalanine from its binding to normal human serum in vitro.