Physicochemical studies of two major subpopulations of low density lipoproteins by differential scanning calorimetry and n.m.r. spectroscopy

M. Bihari-Varga, F. Tölgyesi, J. Pelczer, T. Mok, D. M. Lee

Research output: Contribution to journalArticle

5 Citations (Scopus)

Abstract

Two subpopulations, layer 2 (density 1.025-1.029 g/ml) and layer 3 (density 1.032-1.043 g/ml) of low density lipoproteins (LDL) were isolated from fresh human plasma of normal lipidaemic subjects by density gradient ultracentrifugation. Chemical analyses demonstrated the ratios of triglyceride/cholesterol ester decreased with increasing densities of subfractions. These subfractions together with triglyceride-rich lipoproteins (layer 1, density <1.019 g/ml) were subjected to physicochemical studies by differential scanning calorimetry (d.s.c.) and nuclear magnetic resonance (n.m.r.) spectroscopy. The average transition temperature (Tt) of layer 2 was 34.20±0.83°C and that of layer 3 was 37.25±0.35°C. In addition, many of the layer 3, but not layer 2 and layer 1, samples showed structural alteration and gave rise to an average Tt of 39.18±1.24°C. The structural alteration could be detected with polarizing light microscopy showing birefringent spherulites at body temperature. The peak Tt values obtained by d.s.c. were in good agreement with those by n.m.r. spectroscopy. These results demonstrate the physicochemical heterogeneity within the LDL density region and suggest that layer 3 subpopulation is much more labile than the others.

Original languageEnglish
Pages (from-to)207-212
Number of pages6
JournalInternational Journal of Biological Macromolecules
Volume12
Issue number3
DOIs
Publication statusPublished - 1990

Fingerprint

Transition Temperature
Differential Scanning Calorimetry
LDL Lipoproteins
Nuclear magnetic resonance spectroscopy
Differential scanning calorimetry
Triglycerides
Magnetic Resonance Spectroscopy
Plasma (human)
Cholesterol Esters
Lipoproteins
Optical microscopy
Ultracentrifugation
Body Temperature
Microscopy
Light
Temperature

Keywords

  • cholesterol ester
  • d.s.c.
  • heterogeneity
  • LDL
  • n.m.r.
  • physicochemical
  • structural alteration
  • subfractions
  • Transition temperature

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology

Cite this

Physicochemical studies of two major subpopulations of low density lipoproteins by differential scanning calorimetry and n.m.r. spectroscopy. / Bihari-Varga, M.; Tölgyesi, F.; Pelczer, J.; Mok, T.; Lee, D. M.

In: International Journal of Biological Macromolecules, Vol. 12, No. 3, 1990, p. 207-212.

Research output: Contribution to journalArticle

@article{5c712e6e92e44835a8f8f794f6fee371,
title = "Physicochemical studies of two major subpopulations of low density lipoproteins by differential scanning calorimetry and n.m.r. spectroscopy",
abstract = "Two subpopulations, layer 2 (density 1.025-1.029 g/ml) and layer 3 (density 1.032-1.043 g/ml) of low density lipoproteins (LDL) were isolated from fresh human plasma of normal lipidaemic subjects by density gradient ultracentrifugation. Chemical analyses demonstrated the ratios of triglyceride/cholesterol ester decreased with increasing densities of subfractions. These subfractions together with triglyceride-rich lipoproteins (layer 1, density <1.019 g/ml) were subjected to physicochemical studies by differential scanning calorimetry (d.s.c.) and nuclear magnetic resonance (n.m.r.) spectroscopy. The average transition temperature (Tt) of layer 2 was 34.20±0.83°C and that of layer 3 was 37.25±0.35°C. In addition, many of the layer 3, but not layer 2 and layer 1, samples showed structural alteration and gave rise to an average Tt of 39.18±1.24°C. The structural alteration could be detected with polarizing light microscopy showing birefringent spherulites at body temperature. The peak Tt values obtained by d.s.c. were in good agreement with those by n.m.r. spectroscopy. These results demonstrate the physicochemical heterogeneity within the LDL density region and suggest that layer 3 subpopulation is much more labile than the others.",
keywords = "cholesterol ester, d.s.c., heterogeneity, LDL, n.m.r., physicochemical, structural alteration, subfractions, Transition temperature",
author = "M. Bihari-Varga and F. T{\"o}lgyesi and J. Pelczer and T. Mok and Lee, {D. M.}",
year = "1990",
doi = "10.1016/0141-8130(90)90034-8",
language = "English",
volume = "12",
pages = "207--212",
journal = "International Journal of Biological Macromolecules",
issn = "0141-8130",
publisher = "Elsevier",
number = "3",

}

TY - JOUR

T1 - Physicochemical studies of two major subpopulations of low density lipoproteins by differential scanning calorimetry and n.m.r. spectroscopy

AU - Bihari-Varga, M.

AU - Tölgyesi, F.

AU - Pelczer, J.

AU - Mok, T.

AU - Lee, D. M.

PY - 1990

Y1 - 1990

N2 - Two subpopulations, layer 2 (density 1.025-1.029 g/ml) and layer 3 (density 1.032-1.043 g/ml) of low density lipoproteins (LDL) were isolated from fresh human plasma of normal lipidaemic subjects by density gradient ultracentrifugation. Chemical analyses demonstrated the ratios of triglyceride/cholesterol ester decreased with increasing densities of subfractions. These subfractions together with triglyceride-rich lipoproteins (layer 1, density <1.019 g/ml) were subjected to physicochemical studies by differential scanning calorimetry (d.s.c.) and nuclear magnetic resonance (n.m.r.) spectroscopy. The average transition temperature (Tt) of layer 2 was 34.20±0.83°C and that of layer 3 was 37.25±0.35°C. In addition, many of the layer 3, but not layer 2 and layer 1, samples showed structural alteration and gave rise to an average Tt of 39.18±1.24°C. The structural alteration could be detected with polarizing light microscopy showing birefringent spherulites at body temperature. The peak Tt values obtained by d.s.c. were in good agreement with those by n.m.r. spectroscopy. These results demonstrate the physicochemical heterogeneity within the LDL density region and suggest that layer 3 subpopulation is much more labile than the others.

AB - Two subpopulations, layer 2 (density 1.025-1.029 g/ml) and layer 3 (density 1.032-1.043 g/ml) of low density lipoproteins (LDL) were isolated from fresh human plasma of normal lipidaemic subjects by density gradient ultracentrifugation. Chemical analyses demonstrated the ratios of triglyceride/cholesterol ester decreased with increasing densities of subfractions. These subfractions together with triglyceride-rich lipoproteins (layer 1, density <1.019 g/ml) were subjected to physicochemical studies by differential scanning calorimetry (d.s.c.) and nuclear magnetic resonance (n.m.r.) spectroscopy. The average transition temperature (Tt) of layer 2 was 34.20±0.83°C and that of layer 3 was 37.25±0.35°C. In addition, many of the layer 3, but not layer 2 and layer 1, samples showed structural alteration and gave rise to an average Tt of 39.18±1.24°C. The structural alteration could be detected with polarizing light microscopy showing birefringent spherulites at body temperature. The peak Tt values obtained by d.s.c. were in good agreement with those by n.m.r. spectroscopy. These results demonstrate the physicochemical heterogeneity within the LDL density region and suggest that layer 3 subpopulation is much more labile than the others.

KW - cholesterol ester

KW - d.s.c.

KW - heterogeneity

KW - LDL

KW - n.m.r.

KW - physicochemical

KW - structural alteration

KW - subfractions

KW - Transition temperature

UR - http://www.scopus.com/inward/record.url?scp=0025184675&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0025184675&partnerID=8YFLogxK

U2 - 10.1016/0141-8130(90)90034-8

DO - 10.1016/0141-8130(90)90034-8

M3 - Article

C2 - 2271492

AN - SCOPUS:0025184675

VL - 12

SP - 207

EP - 212

JO - International Journal of Biological Macromolecules

JF - International Journal of Biological Macromolecules

SN - 0141-8130

IS - 3

ER -