Gamma-LpE (gamma-LpE), a @entity4291 -rich lipoprotein that contains apolipoprotein (apo) E as its only protein component, has been proposed to play a role in cellular @entity165 efflux by acting, like pre-beta1-LpA-I, as an initial acceptor of cell-derived @entity165 . In order to further characterize the presence of gamma-LpE in @entity1 plasma, we have separated gamma-LpE by two-dimensional non-denaturing @entity2975 -gradient gel electrophoresis and detected its presence by immunoblotting with 125I-labeled polyclonal anti- @entity2204 antibody. Five species of gamma-LpE were routinely detected in @entity1 plasma, ranging in mean particle diameter from 9.5 to 16.5 nm. The largest proportion of gamma-migrating @entity2204 was associated with gamma-LpE having a diameter of 13.0 nm. Neither the amount of gamma-LpE @entity2204 (representing less than 1-2% of total plasma @entity2204 ) nor the number of gamma-LpE subfractions was different in serum vs. plasma, or was affected by the presence of agents able to inhibit protein dimerization. Gamma-LpE subfractions were present in the plasma of @entity1 having different @entity2204 phenotypes (i.e., @entity2204 2/2, 3/3, or 4/4). Incubation of plasma at 37 degrees C (90 min) caused a significant decrease in plasma gamma-LpE (>80%) that was not dependent on @entity18894 or @entity28371 activity. Storage (at -70 degrees C) of hypertriglyceridemic but not normolipidemic plasma resulted in an increase in gamma-LpE. Freezing of postprandial plasma samples, containing increased amounts of @entity412 -rich lipoproteins (TRL) enriched in @entity2204 , also caused an increase in gamma-LpE. Incubation of VLDL (d < 1.006 g/ml) with lipase resulted in the production of gamma-migrating @entity2204 . These results demonstrate that: 1) different gamma-LpE subfractions exist in @entity1 plasma; 2) the amount of @entity2204 associated with gamma-LpE subfractions is dependent on in vitro conditions of plasma storage; and 3) TRL can act as a source of gamma-LpE @entity2204 in vitro.

In vitro factors affecting the concentration of gamma-LpE (gamma-LpE) in XXXX plasma.

@entity1 :: ('9606', 'Species') :: ['human', 'patients'] @entity2204 :: ('348', 'Gene') :: ['apoE'] @entity4291 :: ('CHEBI:17636', 'Chemical') :: ['sphingomyelin'] @entity18894 :: ('3931', 'Gene') :: ['LCAT'] @entity412 :: ('CHEBI:17855', 'Chemical') :: ['triglyceride'] @entity2975 :: ('CHEBI:51135', 'Chemical') :: ['polyacrylamide'] @entity28371 :: ('1071', 'Gene') :: ['CETP'] @entity165 :: ('MESH:D002784', 'Chemical') :: ['cholesterol']
@entity1 :: (9606,Species) :: ['human']
