Mass Spectrometric Techniques for Sequence and Structural Characterization of Proteins

Monoclonal IgG antibodies (mAbs) are a promising and rapidly growing category of targeted therapeutic proteins. Understanding the dynamic antibody-antigen interactions will greatly facilitate the development of mAb drug therapeutics. The specificity and effector functions of antibodies are highly dependent on their amino acid sequence. Antibodies have sequences that are highly variable and not directly inscribed within the genome; as a result sequencing mAbs remains a challenge.;Protein sequencing is routinely performed via tandem mass spectrometric (MS methods. However, these MS/MS methods rely on the assumption that the protein sequence is encoded within a database. We have grown a model monoclonal antibody and have used several techniques to simplify the antibody for subsequent sequencing studies. De novo sequencing using 157nm photodissociation will be presented as a strategy for sequencing monoclonal antibodies without requiring a sequence database. Further development of antibody drug therapeutics will require the use of accurate and efficient methods to study antibody-epitope interactions. Targeting these interactions can be done using thioimidate crosslinking molecules. The synthesis and characterization of short-length thioimidate crosslinking molecules will be presented as a potential means to enhance protein structural models.