Wisconsin Alumni Research Foundation

Kyle Brown

Song Jin

Ying Ge

Tania Guardado Alvarez

Kevin Buck

The present invention provides photo-cleavable anionic surfactants, particularly 4-hexylphenylazosulfonate (Azo) and sodium 4-hexylphenylazosulfonate derivatives, which can be rapidly degraded upon UV irradiation, for top-down and bottom-up proteomics. These surfactants can effectively solubilize proteins and peptide fragments with performance comparable to sodium dodecyl sulfate (SDS) and are compatible with mass spectrometry analysis of the solubilized proteins and peptide fragments. Top-down proteomic studies using the present photo-cleavable anionic surfactants has allowed the detection of 100-fold more unique proteoforms as compared to controls and has enabled the solubilization of membrane proteins for comprehensive characterization of protein post-translational modifications. In addition, the present photo-cleavable anionic surfactants are also suitable for dissolving polypeptides in bottom-up proteomic experiments including extracellular matrix proteomics, and are suitable as a substitute for SDS in gel electrophoresis.

Photo-cleavable surfactants

Exosomes are a small type of extracellular vesicles containing nucleic acids, lipids, and proteins that are implicated in tumorigenesis, metastasis, and cardiac regeneration, and therefore serve as potentially useful biomarkers from fluids or as vehicles for drug delivery. Global bottom-up mass spectrometry-based proteomics has been previously used to profile exosome cargo for diagnostic purposes. However, the current protocols for MS analysis of extracellular vesicles and exosome proteomics are challenging due to labor-intensive sample preparation, including lengthy digestion times and removal of MS incompatible reagents, and the need for high sensitivity. To address these challenges, the present invention provides a novel, high-throughput strategy for extracellular vesicle analysis and exosome proteomics using a photo-cleavable, anionic surfactant, preferably 4-hexylphenylazosulfonate (Azo). These photo-cleavable, anionic surfactants are able to facilitate high-throughput digestion with minimal sample cleanup for quantitative and highly reproducible analysis.

Growing community of inventors

Madison, WI, United States of America

Kyle Brown