Lipoproteomics II: Mapping of proteins in high-density lipoprotein using two-dimensional gel electrophoresis and mass spectrometry

Abstract

High-density lipoprotein (HDL) is the most abundant lipoprotein particle in the plasma and a negative risk factor of atherosclerosis. By using a proteomic approach it is possible to obtain detailed information about its protein content and protein modifications that may give new information about the physiological roles of HDL. In this study the two subfractions; HDL(2) and HDL(3), were isolated by two-step discontinuous density-gradient ultracentrifugation and the proteins were separated with two-dimensional gel electrophoresis and identified with peptide mass fingerprinting, using matrix-assisted laser desorption/ionisation time of flight mass spectrometry. Identified proteins in HDL were: the dominating apo A-I as six isoforms, four of them with a glycosylation pattern and one of them with retained propeptide, apolipoprotein (apo) A-II, apo A-IV, apo C-I, apo C-II, apo C-III (two isoforms), apo E (five isoforms), the recently discovered apo M (two isoforms), serum amyloid A (two isoforms) and serum amyloid A-IV (six isoforms). Furthermore, alpha-1-antitrypsin was identified in HDL for the first time. Additionally, salivary alpha-amylase was identified as two isoforms in HDL(2), and apo L and a glycosylated apo A-II were identified in HDL(3). Besides confirming the presence of different apolipoproteins, this study indicates new patterns of glycosylated apo A-I and apo A-II. Furthermore, the study reveals new proteins in HDL; alpha-1-antitrypsin and salivary alpha-amylase. Further investigations about these proteins may give new insight into the functional role of HDL in coronary artery diseases.

Nanoparticle size and surface properties determine the protein corona with possible implications for biological impacts

“…The identities of the proteins attached to HDL, LDL, and VLDL have recently been analyzed using proteomics (10)(11)(12)(13)(14)(15)(16). In particular, the list of proteins believed to be associated with HDL particles has grown significantly in recent years (17).…”

Persistent organic pollutants distribution in lipoprotein fractions in relation to cardiovascular disease and cancer

“…Very low/low density lipoprotein (VLDL/LDL) and high density lipoprotein (HDL) were isolated from plasma with density ultracentrifugation as described before (Karlsson et al 2005). To avoid POP interaction with the centrifuge tubes, polycarbonate instead of polyallomer tubes were used.…”

Identification of Critical Paraoxonase 1 Residues Involved in High Density Lipoprotein Interaction

“…Although facilitation of reverse cholesterol transport through cholesterol acceptor activity is considered a major function of HDL particles, ample evidence shows additional functions exist, such as antioxidant, anti-inflammatory, and anti-tumorigenic activities, and the shuttling of microRNAs or lipid-signaling molecules (10 -16). HDL is a highly heterogeneous array of distinct particles, with differing associated proteome and peptidome (17)(18)(19)(20)(21)(22). In addition to exchangeable apolipoproteins, early proteomics studies revealed the HDL-associated proteome includes known participants critical to hemostasis and thrombosis, innate and adaptive immune function, growth factors and various receptors, and hormone-associated proteins (17,20).…”

“…HDL is a highly heterogeneous array of distinct particles, with differing associated proteome and peptidome (17)(18)(19)(20)(21)(22). In addition to exchangeable apolipoproteins, early proteomics studies revealed the HDL-associated proteome includes known participants critical to hemostasis and thrombosis, innate and adaptive immune function, growth factors and various receptors, and hormone-associated proteins (17,20). In the years that have followed since the original HDL proteomics studies, subsequent reports have confirmed and expanded upon these earlier findings, revealing a remarkably complex HDL-associated proteome that can differ as a function of disease status or susceptibility (23)(24)(25).…”