Free sulfhydryl content is one of the important attributes of proteins including monoclonal antibodies(mAb). The detection of free sulfhydryls in proteins can present incomplete disulfide bond formation, reflect cysteine residues available for conjugation, and provide insights into protein stability and structure. This is crucial for early process development as well as late-stage manufacturing oversight.
Yaohai Bio-Pharma offers free sulfhydryl groups service based on Ellman’s assay which derivatizes sulfhydryls using (5,5′-dithio-bis- [2-nitrobenzoic acid]).
We have been involved in the Protein Structural Characterization of various large molecules, including Recombinant Subunit Vaccines, Nanobodies/VHHs/ Single-domain Antibodies (sdAbs), Antibody Fragments, Hormones/Peptides, Cytokines, Growth Factors (GF), Enzymes, Collagens, etc.
Regulatory Requirements for Free Sulfhydryl Groups
ICH Q6B, If, based on the gene sequence for the desired product, cysteine residues are expected, the number and positions of any free sulfhydryl groups and/or disulfide bridges should be determined, to the extent possible. Peptide mapping (under reducing and non-reducing conditions), mass spectrometry, or other appropriate techniques may be useful for this evaluation.
Analytical Methods
| Analysis |
Methods |
| Free Sulfhydryls Groups |
Ellman’s assay |
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