Journal of Lipid Research, Vol 30, 641-650, Copyright © 1989 by Lipid Research, Inc.
Low density lipoprotein heterogeneity in the cebus monkey
DL Puppione, RJ Nicolosi, MC Kowala and VN Schumaker
Department of Clinical Sciences, University of Lowell, MA 01854.
In studies of cebus monkey plasma lipoproteins, we have used an
ultracentrifugally generated density gradient to isolate two distinct
species of low density lipoproteins (LDL). Compositional analyses revealed
that each of the ultracentrifugally isolated fractions was enriched in
cholesteryl esters and contained a single apolipoprotein which in terms of
its mobility on SDS gels corresponded to apolipoprotein B-100, the major
apolipoprotein of human LDL. Hydrodynamic measurements carried out in the
analytical ultracentrifuge showed that F1.20 values were 30.0 for LDL1 and
23.5 for LDL2. In a solution of density 1.0069 g/ml, the sedimentation
rates were 5.9 and 7.2 S for LDL1 and LDL2, respectively. In addition to
sedimentation velocity data, we describe a new approach for using these
same data to obtain calculated values for molecular weight. The hydrated
densities calculated for the two fractions were 1.033 and 1.045 g/ml and
calculated molecular weights were 3.08 million for LDL1 and 2.42 million
for LDL2. Hydrated density values were in excellent agreement with those
calculated from compositional data. Electron microscopy data showed that
LDL1 had a larger mean diameter of 26.7 nm than LDL2 which had a diameter
of 19.3 nm. Native gel electrophoretic analyses of the two LDL fractions in
3.5% acrylamide showed that, consistent with its size, LDL1 had slower
mobility than LDL2.