Tangier disease: defective recombination of a specific Tangier apolipoprotein A-I isoform (pro-apo A-i) with high density lipoproteins.

Abstract

Isoforms of apolipoprotein A-I (apo A-I) from subjects with Tangier disease were characterized, and their ability to recombine with normal high density lipoproteins (HDL) was studied. In contrast to normal serum, in which isoprotein 4 is the dominant species [79 +/- 1.8% (mean +/- SD)], the Tangier serum contained much less total apo A-I (approximately equal to 1% of that in normal serum), and isoproteins 2 and 4 were present in roughly equivalent amounts (35.3 +/- 2.5% and 42.7 +/- 3.6%, respectively). The Tangier isoprotein 2 was shown to correspond to pro-apo A-I, having a six-amino acid amino-terminal extension with the sequence: Arg-His-Phe-Trp-Gln-Gln-. The Tangier isoprotein 4 had the same amino-terminal sequence as normal circulating plasma apo A-I. Its association with normal HDL (70%) was similar to the association of normal apo A-I with HDL (80-90%) in recombination experiments. In marked contrast to this behavior, very little (less than 10%) of Tangier isoprotein 2 (pro-apo A-I) associated with HDL in recombination experiments. These results suggest that the underlying defect in Tangier disease may be a faulty conversion of pro-apo A-I to mature apo A-I, either due to a defect in the converting enzyme activity or to a further specific structural defect in Tangier apo A-I. The failure of Tangier pro-apo A-I to associate with HDL may be at least partially responsible for the HDL deficiency in Tangier subjects.

• Authors: G Schmitz, G Assmann, S C Rall Jr, R W Mahley
• Journal: Proceedings of the National Academy of Sciences of the United States of America (Proc Natl Acad Sci U S A) Vol. 80 Issue 19 Pg. 6081-5 (Oct 1983) ISSN: 0027-8424 [Print] United States
• PMID: 6412234 (Publication Type: Journal Article, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Apolipoprotein A-I
• Apolipoprotein A-II
• Apolipoproteins
• Apolipoproteins A
• Lipoproteins, HDL
• Peptide Fragments
• Protein Precursors

Topics

• Amino Acid Sequence
• Apolipoprotein A-I
• Apolipoprotein A-II
• Apolipoproteins (blood, isolation & purification)
• Apolipoproteins A
• Female
• Humans
• Hypolipoproteinemias (blood)
• Lipoproteins, HDL (blood)
• Middle Aged
• Peptide Fragments (analysis)
• Protein Precursors
• Tangier Disease (blood)