The in vitro metabolism of high density lipoproteins (HDL) in carriers of the apolipoprotein AIMilano (apoAIM) mutant was investigated during incubation of whole plasma and isolated lipoprotein fractions. A reduced cholesterol esterification (16.5 versus 25.0% for controls) and a decreased exchange of lipids between HDL and lower density lipoproteins was observed during incubation (6 h at 37°C) of AIM plasma. Control HDL3 were converted to larger, faster-floating HDL particles, whereas only a fraction of AIM HDL3 followed the same pathway. Incubations were also carried out by mixing HDL3 from controls and AIM carriers with a lipoprotein-depleted plasma fraction in the presence of triglyceride-rich particles isolated from Intralipid. AIM HDL3 again showed a reduced capacity for lipid exchange; some HDL3 particles followed a "normal" conversion to faster-floating, larger HDL, whereas the small AIM HDL3 were not modified, indicating that AIM HDL3 are a mixture of metabolically functional and nonfunctional particles. Following transformation of the apoAIM homo- and heterodimers into their normal counterparts, i.e. monomeric apoAI and -AII, by reduction and carboxamidomethylation of AIM HDL3, the modified HDL3 behave like control HDL3 during incubation with lipoprotein-depleted plasma and triglyceride-rich particles. The presence of AIM dimers is most likely responsible for the increased HDL3 stability in the AIM carriers, indicating that apolipoprotein composition plays a major role in HDL particle interconversion.
|Titolo:||APOLIPOPROTEIN AIMILANO - DISULFIDE-LINKED DIMERS INCREASE HIGH-DENSITY-LIPOPROTEIN STABILITY AND HINDER PARTICLE INTERCONVERSION IN CARRIER PLASMA|
FRANCESCHINI, GUIDO (Primo)
CALABRESI, LAURA (Secondo)
SIRTORI, CESARE (Penultimo)
|Settore Scientifico Disciplinare:||Settore BIO/14 - Farmacologia|
|Data di pubblicazione:||1990|
|Appare nelle tipologie:||01 - Articolo su periodico|