Characterization of apolipoprotein M isoforms in low-density lipoprotein
2006 (English)In: Journal of proteome research, ISSN 1535-3893 (print), 1535-3907 (online), Vol. 5, no 10, 2685-2690 p.Article in journal (Refereed) Published
Apo M is a recently discovered human lipoprotein thought to be involved in the metabolism of lipids and lipoprotein particles. Here, a proteomic approach was applied to examine the glycosylation pattern of apo M in human LDL. We treated LDL proteins with N-glycosidase or neuraminidase, studied mobility shifts of Apo M by two-dimensional gel electrophoresis, and different isoforms were then identified with mass spectrometry. This way, we demonstrated the presence of five isoforms of apo M in LDL: three that are both N-glycosylated and sialylated, one that is N-glycosylated but not sialylated, and one that is neither N-glycosylated nor sialylated. As judged from the examination of LDL from 20 healthy human subjects, the three N-glycosylated and sialylated forms are most abundant (80−100% of the total apo M in LDL) whereas the unsialylated and unglycosylated variants constitute at most 20%. Comparative analysis showed that the same five isoforms of apo M are also present in HDL. Further studies aiming at elucidating the role of apo M in health and disease will have to take this polymorphism of apo M proteins into account.
Place, publisher, year, edition, pages
2006. Vol. 5, no 10, 2685-2690 p.
apolipoprotein M, apo M, low-density lipoprotein, LDL, two-dimensional gel electrophoresis, 2-DE, MALDI-TOF mass spectrometry, glycosylations, sialylations
National CategoryMedical and Health Sciences
IdentifiersURN: urn:nbn:se:liu:diva-14353DOI: 10.1021/pr060180xOAI: oai:DiVA.org:liu-14353DiVA: diva2:23301