In vitro studies on origin and site of action of enzyme activity responsible for conversion of human proapoprotein A-I into apoprotein A-I

FEBS Lett. 1984 May 7;170(1):109-13. doi: 10.1016/0014-5793(84)81379-4.

Abstract

Human hepatocellular carcinoma cells (Hep G2) were shown to secrete apo A-I as a proprotein . No apo A-I synthesis could be detected with endothelial cells from human umbilical cord veins. Conversion of proapo A-I into apo A-I is a slow (of the order of hours) process, mediated by a Ca2+/Mg2+-dependent enzyme which is present on the surface of plasma lipoprotein particles, endothelial cells and Hep G2 cells, and is probably synthesized by Hep G2 cells.

MeSH terms

  • Apolipoprotein A-I
  • Apolipoproteins / metabolism*
  • Apolipoproteins A*
  • Blood
  • Calcium / metabolism
  • Carcinoma, Hepatocellular / enzymology*
  • Cell Line
  • Endothelium / enzymology
  • Female
  • Humans
  • Isoelectric Focusing
  • Lipoproteins / metabolism
  • Liver Neoplasms
  • Magnesium / metabolism
  • Molecular Weight
  • Pregnancy
  • Protein Precursors*
  • Umbilical Veins / cytology

Substances

  • Apolipoprotein A-I
  • Apolipoproteins
  • Apolipoproteins A
  • Lipoproteins
  • Protein Precursors
  • Magnesium
  • Calcium