Myeloperoxidase binds to low-density lipoprotein: potential implications for atherosclerosis

FEBS Lett. 2000 Dec 29;487(2):176-80. doi: 10.1016/s0014-5793(00)02227-4.

Abstract

Myeloperoxidase (MPO), an abundant heme enzyme released by activated phagocytes, catalyzes the formation of a number of reactive species that can modify low-density lipoprotein (LDL) to a form that converts macrophages into lipid-laden or 'foam' cells, the hallmark of atherosclerotic lesions. Since MPO has been shown to bind to a number of different cell types, we investigated binding of MPO to LDL. Using the precipitation reagents phosphotungstate or isopropanol, MPO co-precipitated with LDL, retaining its catalytic activity. The association of MPO with LDL was confirmed using native gel electrophoresis. MPO was also found to co-precipitate with apolipoprotein B-100-containing lipoproteins in whole plasma. No precipitation of MPO was observed in lipoprotein-deficient plasma, and there was a dose-dependent increase in precipitation following addition of LDL to lipoprotein-deficient plasma. Binding of MPO to LDL could potentially enhance site-directed oxidation of the lipoprotein and limit scavenging of reactive oxygen species by antioxidants.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Arteriosclerosis / blood*
  • Humans
  • Kinetics
  • Leukocytes / enzymology
  • Lipoproteins, LDL / blood*
  • Lipoproteins, LDL / chemistry
  • Lipoproteins, LDL / isolation & purification
  • Peroxidase / blood*
  • Peroxidase / chemistry
  • Peroxidase / isolation & purification
  • Protein Binding
  • Serum Albumin

Substances

  • Lipoproteins, LDL
  • Serum Albumin
  • Peroxidase