SELDI-TOF mass spectrometry of high-density lipoprotein

Background: High-Density Lipoprotein ( HDL), one of the main plasma lipoproteins, serves as a docking station for proteins involved in inflammation, coagulation, and lipid metabolism. Methods: To elucidate the protein composition of HDL, we employed SELDI-TOF mass spectrometry as a potential high-throughput proteomic candidate for protein profiling of HDL. HDL derived from normolipemic individuals was captured on PS20 protein-chips using covalently bound antibodies against apo A-I or A-II. Results: After optimisation, on-chip capture of HDL particles directly from plasma or from pre-purified HDL resulted in comparable fingerprints confirming specific capture of HDL. Depending on the capture antibody some differences in the fingerprint were observed. The most detailed fingerprint was observed up to 50 kDa; approximately 95 peaks were detected in the 3 - 50 kDa molecular mass range. Between 50 and 160 kDa, 27 more peaks were detected. Conclusion: Based on these results, SELDI-TOF MS may be a suitable high-throughput candidate for HDL protein profiling and marker search. This approach may be used to i) investigate the underlying mechanisms that lead to increased atherothrombotic risk and ii) to investigate the atherothrombotic state of an individual.