Automated sample preparation for CE-SDS.

Traditionally, CE with SDS (CE-SDS) places many restrictions on sample composition. Requirements include low salt content, known initial sample concentration, and a narrow window of final sample concentration. As these restrictions require buffer exchange for many sample types, sample preparation is often tedious and yields poor sample recoveries.

Automated tryptic digestion procedure for HPLC/MS/MS peptide mapping of immunoglobulin gamma antibodies in pharmaceutics.

The rapid growth of antibody drugs and drug candidates in the biopharmaceutical industry has created a demand for automated proteolytic digestion to assist in pharmaceutical stability studies, identity assays and quality control of these therapeutic proteins. Here, we describe the development of a fully automated proteolytic digestion procedure for monoclonal antibodies in solution, which requires a high concentration of denaturants for unfolding. The antibody samples were placed in a 96-well plate or in 0.

Investigation of N-terminal glutamate cyclization of recombinant monoclonal antibody in formulation development.

The N-terminal glutamic acid (Glu) can be cyclized to form pyroglutamate (pGlu). Recent studies have suggested that N-terminal pGlu formation is an important posttranslational or co-translational event and is greatly facilitated by the enzyme glutaminyl cyclase, although the impact of the N-terminal cyclization on the potency and overall stability of mAbs is not been well known. Since most recombinant monoclonal antibodies (mAbs) contain glutamic acid and/or glutamine at their N-terminus, understanding the cyclization mechanisms may shed light on the factors that control the pGlu formation in therapeutic mAb development.

Formation of pyroglutamic acid from N-terminal glutamic acid in immunoglobulin gamma antibodies.

The status of the N-terminus of proteins is important for amino acid sequencing by Edman degradation, protein identification by shotgun and top-down techniques, and to uncover biological functions, which may be associated with modifications. In this study, we investigated the pyroglutamic acid formation from N-terminal glutamic acid residues in recombinant monoclonal antibodies. Almost half the antibodies reported in the literature contain a glutamic acid residue at the N-terminus of the light or the heavy chain.