Presentation description

Asparagine (Asn) has been shown to be involved in causing prions by deamination and/or metal binding in Alzheimer's, Parkinson's, cataracts, and diabetes. This deamination usually forms L or D-succinimidyl ring in solution phase; however, gas phase mass spectrometer (MS) shows there are more structures that can be formed. Using a Guided Ion Beam tandem Mass Spectrometer (GIBMS), one can determine thermodynamic information of the major dissociation products of (methylated-AsnSer)+. We also use Gaussian16 to model dissociation mechanisms of predicted products (deamidation, dehydration, 2nd deamidation, and loss of asparagine) and single point energies at various levels of theory to compare with the experimental data. We will use these modeled dissociation mechanisms with previously collected GIBMS data to determine the thermodynamics of decomposition. Previous work of (AsnSer)+ will be directly compared to better understand how tagging the peptide with a methyl group impact the dissociation observed, specifically with the dehydration.