Identification of a distinct human high-density lipoprotein subspecies defined by a lipoprotein-associated protein, K-45. Identity of K-45 with paraoxonase
| Autor: | Sylvia Messmer, Francisco Barja, Marie-Claude Blatter, Richard James, Daniel Pometta |
|---|---|
| Rok vydání: | 1993 |
| Předmět: |
Apolipoprotein B
medicine.drug_class Molecular Sequence Data Peptide Chemical Fractionation Monoclonal antibody Biochemistry Chromatography Affinity chemistry.chemical_compound High-density lipoprotein Affinity chromatography medicine Humans Amino Acid Sequence Isoelectric Point Peptide sequence Immunosorbent Techniques chemistry.chemical_classification Apolipoprotein A-I Molecular mass biology Aryldialkylphosphatase Cholesterol HDL Phosphoric Monoester Hydrolases Molecular Weight chemistry Chromatography Gel biology.protein Regression Analysis lipids (amino acids peptides and proteins) Lipoproteins HDL Ultracentrifugation Lipoprotein |
| Zdroj: | European Journal of Biochemistry. 211:871-879 |
| ISSN: | 1432-1033 0014-2956 |
| DOI: | 10.1111/j.1432-1033.1993.tb17620.x |
| Popis: | In an attempt to provide immunological tools for subfractionation of high-density lipoproteins (HDL), monoclonal antibodies were raised against HDL complexes. Two clones identified a peptide, provisionally named K-45 (pI 4.5-4.9; molecular mass 45 kDa, range 42-48 kDa), whose plasma distribution and lipoprotein association were fully characterised. Gel filtration localised the peptide to the HDL region of human plasma where it co-eluted with apolipoprotein (apo) A-I, the structural protein of HDL. Complementary studies employing immunoabsorption with anti-(apo A-I) antibodies removed 90% of K-45 from plasma: conversely, anti-(apo A-II) antibodies eliminated only 10% of K-45. Immunoaffinity chromatography on an anti-(K-45) column revealed that the peptide was present in a distinct HDL subsepecies containing three major proteins: K-45, apo A-I and clusterin or apo J. The lipoprotein nature of the bound fraction was indicated by electron microscopy (diameter 9.6 +/- 3.3 nm) and quantification of lipids, the latter showing an unusually high triacyglycerol concentration. Plasma concentrations of K-45 were positively correlated with apo A-I and HDL-cholesterol and negatively correlated with apo B and total cholesterol. Thus, the peptide appears to be linked, directly or indirectly, to processes which give rise to an anti-atherogenic lipid profile. After completion of the present studies, an N-terminal sequence identical to that of K-45 was reported in recently isolated cDNA clones. These clones encode paraoxonase. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|