Immunochemistry of Human Plasma High Density Lipoproteins. Radioimmunoassay of Rpolipoprotein A-II

S. J.T. Mao, Antonio Gotto, R. L. Jackson

Research output: Contribution to journalArticlepeer-review

29 Scopus citations


Apolipoprotein A-II (ApoA-II) is a major apoprotein of human plasma high density lipoproteins (HDL). The apoprotein has two identical chains of known amino acid sequence; the chains are linked by a single disulfide bond. In the present study, we have developed a specific radioimmunoassay for apoA-II that provides a convenient and reproducible method for measuring 10-100 ng of apoprotein. The assay was based on the competition of apoprotein with isotopically labeled [125I]apoA-II. Dioxane (52%) was used to separate antibody bound [125I]apoA-II from the free apoprotein. The assay has enabled us to begin studies directed toward mapping-out of the antigenic reactive regions of apoA-II. It has also allowed us to determine the interrelationship between the lipid-binding sites and the antigenic sites of the molecule. The antigenic reactivity of apoA-II was approximately the same in HDL and phospholipid- apoA-II complexes as that of the free apoprotein. However, succinylation of apoA-II was associated with a marked decrease in antigenic reactivity.

Original languageEnglish (US)
Pages (from-to)4127-4131
Number of pages5
Issue number18
StatePublished - Sep 1 1975

ASJC Scopus subject areas

  • Biochemistry


Dive into the research topics of 'Immunochemistry of Human Plasma High Density Lipoproteins. Radioimmunoassay of Rpolipoprotein A-II'. Together they form a unique fingerprint.

Cite this