In vitro interactions between low density lipoprotein from hyperapobetalipoproteinemic plasma and arterial wall proteoglycans.
OBJECTIVE
To examine the interactions of low density lipoprotein-B (LDL-B) with proteoglycans (PG) in vitro.


METHODS
The PG were isolated from human aortas, removed at autopsy by a combination of extraction with 4M guanidine-Tris buffer containing protease inhibitors and fractionation on a DEAE-Sephacel ion-exchange chromatography column. LDL and LDL-B from healthy or hyperapobetalipoproteinemic sera, respectively, were isolated by standard density flotation techniques followed by radioiodination. Radiolabelled lipoproteins (LP) were incubated with proteoglycans at 4 or 37 degrees C in a low ionic strength buffer with or without addition of polyethylene glycol (PEG) which was used to enhance precipitation of the resulting LP-PG complexes.


RESULTS
Data revealed that a specific ratio of LP to PG is a prerequisite for optimal interactions between these macromolecules. Further, it was observed that LDL-B forms fewer precipitable complexes than normal LDL at 4 degrees C. However, at physiological temperature or with the addition of PEG, precipitation of the two LDLs was equal.


CONCLUSIONS
LDL and LDL-B showed equal reactivity with PG in terms of precipitable complexes.
Wasty
F
F
Department of Pathology, Royal Victoria Hospital, Montreal, Quebec.
Alavi
M Z
MZ
Li
Z
Z
Cianflone
K
K
Sniderman
A D
AD
Moore
S
S
D001011:Aorta / Q000737:chemistry*; D011232:Chemical Precipitation; D004353:Drug Evaluation, Preclinical; D004347:Drug Interactions; D006801:Humans; D006938:Hyperlipoproteinemia Type II / Q000097:blood*; D008077:Lipoproteins, LDL / Q000097:blood / Q000494:pharmacology* / Q000502:physiology; D011509:Proteoglycans / Q000737:chemistry / Q000494:pharmacology* / Q000502:physiology; D012995:Solubility
D008077:Lipoproteins, LDL; D011509:Proteoglycans