Quenching of tryptophan fluorescence in rabbit and bovine IgG

✍ Scribed by R. J. Hill

• Publisher: John Wiley and Sons
• Year: 1973
• Tongue: English
• Weight: 537 KB
• Volume: 3
• Category: Article
• ISSN: 0014-2980
• DOI: 10.1002/eji.1830030603

✦ Synopsis

Abstract

IgG, Fab fragments and poly‐D, L‐alanylated IgG prepared from normal rabbit sera show a decrease in fluorescence on titration down from pH 9 to 3. A qualitatively similar behavior is seen in a preparation of normal bovine IgG in both the native and heat‐denaturated state. This decrease in fluorescence is believed to be due to collisional quenching of tryptophan fluorescence by protonated amino acid residues. Since tryptophan is believed to be an integral part of the antigen‐binding site, these findings open the possibility of using tryptophan fluorescence to follow conformational changes in the antibody molecule.