Rapid Affinity Enrichment of Human Apolipoprotein A‑I Associated Lipoproteins for Proteome Analysis

Isolation
of high density lipoproteins (HDL) for structural and
functional studies typically relies on ultracentrifugation techniques,
which are time-consuming and difficult to scale. With emerging interest
in the clinical relevance of HDL structure and function to cardiovascular
disease, a significant gap exists between current and desirable sample
preparation throughput. To enable proteomic studies of HDL with large
clinical cohorts, we have developed an affinity enrichment approach
that relies on the association of histidine-tagged, lipid free ApoA-I
with HDL followed by standard metal chelate chromatography. Characterization
of the resulting affinity-enriched ApoA-I associated lipoprotein (AALP)
pool using biochemical, electrophoretic, and proteomic analysis demonstrates
that the isolated material is closely related in structural features,
lipid content, protein complement, and relative protein distribution
to HDL isolated by ultracentrifugation using sequential density adjustment.
The simplicity of the method provides avenues for high-throughput
analysis of HDL associated proteins.