Transformation of high density lipoprotein 2 particles by hepatic lipase and phospholipid transfer protein.
High density lipoprotein 2 (HDL2) was incubated with phospholipid transfer protein (PLTP) or with hepatic lipase (H-TGL), and the incubation products were separated into a d < 1.22 g/ml and a d > 1.22 g/ml fractions. The d < 1.22 g/ml fraction produced by PLTP was larger, had lower apolipoprotein A-I and higher lipid and apolipoprotein A-II content than native HDL2. The d > 1.22 g/ml fraction represented 30% of the initial HDL2 protein and consisted of small, apolipoprotein A-I and phospholipid-rich particles, with a high sphingomyelin:phosphatidylcholine ratio. Incubation with H-TGL led to a d < 1.22 g/ml fraction which was comparable to native HDL2 regarding size and chemical composition. The d > 1.22 g/ml particles represented only 5% of the initial HDL2 protein and had slightly higher diameter and sphingomyelin:phosphatidylcholine ratio than those produced by PLTP. Enrichment of HDL2 with triglyceride prior to incubation increased the amount of protein released into the d > 1.22 g/ml fraction (20%) but had no effect on size and chemical composition of the particles. We conclude that PLTP and H-TGL promote the formation of small, pre-beta-like HDL particles from HDL2.
Marques-Vidal
P
P
National Public Health Institute, Department of Biochemistry, Helsinki, Finland.
Jauhiainen
M
M
Metso
J
J
Ehnholm
C
C
D017301:Ca(2+) Mg(2+)-ATPase / Q000378:metabolism; D002352:Carrier Proteins / Q000378:metabolism*; D053480:Cholesterol Ester Transfer Proteins; D004587:Electrophoresis, Agar Gel; D006023:Glycoproteins; D006801:Humans; D007700:Kinetics; D008049:Lipase / Q000378:metabolism*; D008075:Lipoproteins, HDL / Q000378:metabolism*; D053439:Lipoproteins, HDL2; D008099:Liver / Q000201:enzymology; D008565:Membrane Proteins / Q000378:metabolism*; D049294:Phospholipid Transfer Proteins; D010743:Phospholipids / Q000378:metabolism*; D014280:Triglycerides / Q000378:metabolism
C506642:CETP protein, human; D002352:Carrier Proteins; D053480:Cholesterol Ester Transfer Proteins; D006023:Glycoproteins; D008075:Lipoproteins, HDL; D053439:Lipoproteins, HDL2; D008565:Membrane Proteins; D049294:Phospholipid Transfer Proteins; D010743:Phospholipids; D014280:Triglycerides; D008049:Lipase; D017301:Ca(2+) Mg(2+)-ATPase