Zsuzsanna Kuklenyik
Centers for Disease Control and Prevention, USA
Title: Identification and quantification of proteins participating in apoA-1 and apoB-100 mediated cholesterol transport by field-flow fractionation and LC-MS/MS analysis
Biography
Biography: Zsuzsanna Kuklenyik
Abstract
Lipid homeostasis in vivo is mediated by several lipoprotein sub-species, commonly classified as high density and low density lipoproteins (HDL and LDL). The two common apolipoproteins, ApoA-1 and ApoB-100 are associated with numerous exchangeable lipids and proteins in various compositions. Because of their number and complexity, the analysis of lipoprotein sub-species in plasma by bottom-up proteomics approaches requires pre-analytical physical fractionation. Asymmetric flow-field flow fraction (AF4) is a gentle separation technique based on hydrodynamic size. AF4 allows size separation of intact lipoprotein sub-species and fraction collection. LC-MS/MS analysis of the individual fractions can provide unique concentration versus hydrodynamic size profiles for each protein constituent. Deconvolution of the concentration versus size profiles of ApoA-1 and ApoB-100 allows quantitative deduction of the particle number of lipoprotein sub-species. The probability of associations of proteins with ApoA-1 and ApoB-100 containing sub-species was evaluated based on size profile overlap with those of Apo-A-1 or ApoB-100 sub-species, size derived maximum possible total molecular weight, and protein-ApoA-1 or protein-ApoB-100 concentration correlations measured in multiple serum samples with wide range of cholesterol and triglyceride levels. Based on these criteria proteins can be included or excluded as participants of ApoA-1 and ApoB-100 mediated lipid metabolism pathways.