Low-density lipoprotein binding affinity of arterial wall proteoglycans: characteristics of a chondroitin sulfate proteoglycan subfraction
| Autor: | Parakat Vijayagopal, Karen Eberle, Bhandaru Radhakrishnamurthy, Gerald S. Berenson, Sathanur R. Srinivasan |
|---|---|
| Rok vydání: | 1989 |
| Předmět: |
Size-exclusion chromatography
Biophysics Dermatan Sulfate Biochemistry Dermatan sulfate chemistry.chemical_compound Endocrinology Affinity chromatography Centrifugation Density Gradient medicine Animals Chondroitin Chondroitin sulfate Amino Acids Aorta Chromatography Chondroitin Lyases biology Heparin Chondroitin Sulfates Lipoproteins LDL Molecular Weight carbohydrates (lipids) Chondroitin Sulfate Proteoglycans chemistry Proteoglycan Chondroitin sulfate proteoglycan biology.protein Cattle Electrophoresis Polyacrylamide Gel Proteoglycans lipids (amino acids peptides and proteins) medicine.drug |
| Zdroj: | Biochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism. 1006:159-166 |
| ISSN: | 0005-2760 |
| DOI: | 10.1016/0005-2760(89)90190-2 |
| Popis: | The characteristics of an arterial wall chondroitin sulfate proteoglycan (CS-PG) subfraction that binds avidly to low-density lipoproteins (LDL) was studied. A large CS-PG was extracted from bovine aorta intima-media under dissociative conditions, purified by density-gradient centrifugation and gel filtration chromatography, and further subfractionated by affinity chromatography on LDL-agarose. A proteoglycan subfraction, representing 25% of the CS-PG, showed an elution profile (with dissociation from LDL-agarose occurring between 0.5 and 1.0 M NaCl) corresponding to that of heparin, heretofore considered to be the most strongly binding glycosaminoglycan with LDL. The proteoglycan subfraction which migrated as a single band on composite agarose-polyacrylamide gel electrophoresis contained chondroitin 6-sulfate, chondroitin 4-sulfate and dermatan sulfate in a proportion of 70:22:8. The core protein of the proteoglycan had an apparent molecular weight of 245,000, and contained approx. 33 glycosaminoglycan chains with an average molecular weight of 32,000. The CS-PG subfraction, like heparin, formed insoluble complexes in the presence of 30 mM Ca2+. Complexing of LDL with proteoglycan resulted in two classes of interactions with 0.1 and 0.3 proteoglycan monomer bound per LDL particle characterized by an apparent Kd of 4 and 21 nM, respectively. This indicates that multiple LDL particles bind to single proteoglycan monomers even at saturation. In contrast, LDL-heparin interactions showed a major component characterized by an apparent Kd of 151 nM and a Bmax of 9 heparin molecules per LDL particle. The occurrence of a potent LDL-binding proteoglycan subfraction within the family of arterial CS-PG may be of importance in terms of lipid accumulation in atherogenesis. |
| Databáze: | OpenAIRE |
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