Glycosylation and Sialylation of Macrophage-derived Human Apolipoprotein E Analyzed by SDS-PAGE and Mass Spectrometry

• DOI: 10.1074/mcp.m900430-mcp200
• Publication Date: 2010-05-29T03:15:14Z
• Authors: Youra Lee; Maaike Kockx; Mark J. Raftery; Wendy Jessup; Renate Griffith; Leonard Kritharides
• Keywords: N-linked glycosylation

Apolipoprotein E (apoE) is a 34-kDa glycoprotein secreted from various cells including hepatocytes and macrophages plays an important role in remnant lipoprotein clearance, immune responses, Alzheimer disease, atherosclerosis. Cellular apoE plasma exist as multiple glycosylated sialylated glycoforms with being less glycosylated/sialylated than cell-derived apoE. Some of the glycan structures on are characterized; however, more complicated cellular/secreted remain unidentified. We investigated glycosylation sialylation cellular primary human by one- two-dimensional gel electrophoresis mass spectrometry. Our results identify eight different (HexNAc)(2)-Hex(2)-(NeuAc)(2) most complex detected Thr(194) both Four additional glycans were identified apoE(283-299), using beta-elimination/alkylation methylamine vitro, we Ser(290) novel site attachment. Comparison same donor confirmed that extensively Given importance C terminus regulating solubility, stability, lipid binding, these may have implications for our understanding biochemistry.