BioAnalytical Mass Spectrometry
Project 1: Determination of Oligosaccharides in the egg jelly of Xenopus eggs.
We are developing methods to characterize mucin-type oligosaccharides by characterizing the mucins of the Xenopus frog oocyte. The egg jelly coats the eggs of Xenopus frogs and are involved in a number of processes including fertilization. The oligosaccharides play a key role in recognition. We are in the process of characterizing the O-linked oligosaccharides in the egg jelly of Xenopus laevis, tropicalis and borealis. We are characterizing the diversity of oligosaccharides to determine what role they play in the fertilization processes.
Project 2: Determination of Protein Oxidation Sites
Protein oxidation is linked to cellular stress, aging, and disease. We are developing a novel system to identify the exact oxidized residues on a model protein, human serum albumin (HSA). Specially designed Element-Coded Affinity Mass Tags can be: 1) used to tag specific oxidized residues, 2) used to affinity purify the tagged peptides using the 2D12.5 antibody, and 3) loaded with a variety of rare earth elements to generate distinctive mass signatures. The tagged peptides are analyzed using a nanoLC-FTICR. By using multiple stages of separation, we hope to eventually detect low levels of oxidation in complex biological samples. We have demonstrated this as a general method to map protein surfaces in preparation for studying protein-protein interactions.
