Merck

Characterization of trisulfide modification in antibodies.

Analytical biochemistry (2010-01-21)
Sheng Gu, Dingyi Wen, Paul H Weinreb, Yaping Sun, Lihe Zhang, Susan F Foley, Rashmi Kshirsagar, David Evans, Sha Mi, Werner Meier, R Blake Pepinsky
ABSTRACT

Trisulfides are a posttranslational modification formed by the insertion of a sulfur atom into a disulfide bond. Although reports for trisulfides in proteins are limited, we find that they are a common modification in natural and recombinant antibodies of all immunoglobulin G (IgG) subtypes. Trisulfides were detected only in interchain linkages and were predominantly in the light-heavy linkages. Factors that lead to trisulfide formation and elimination and their impact on activity and stability were investigated. The peptide mapping methods developed for characterization and quantification of trisulfides should be applicable to any antibody and can be easily adapted for other types of proteins.

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
IgG2, Kappa from human myeloma plasma, purified immunoglobulin, >95% (SDS-PAGE)