Abstract
The interaction of apolipoprotein H (Apo H) with lipid membrane has been considered to be a basic mechanism for the biological function of the protein. Previous reports have demonstrated that Apo H can interact only with membranes containing anionic phospholipids. Here we study the membrane-induced conformational change of Apo H by CD spectroscopy with two different model systems: anionic-phospholipid-containing liposomes [such as 1,2-dimyristoyl-sn-glycero-3-phosphoglycerol (DMPG) and cardiolipin], and the water/methanol mixtures at moderately low pH, which mimic the micro-physicochemical environment near the membrane surface. It is found that Apo H undergoes a remarkable conformational change on interaction with liposomes containing anionic phospholipid. To interact with liposomes containing DMPG, there is a 6.8% increase in α-helix in the secondary structures; in liposomes containing cardiolipin, however, there is a 12.6% increase in α-helix and a 9% decrease in β-sheet. The similar conformation change in Apo H can be induced by treatment with an appropriate mixture of water/methanol. The results indicate that the association of Apo H with membrane is correlated with a certain conformational change in the secondary structure of the protein.
Original language | English (US) |
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Pages (from-to) | 103-106 |
Number of pages | 4 |
Journal | Biochemical Journal |
Volume | 348 |
Issue number | 1 |
DOIs | |
State | Published - May 15 2000 |
Externally published | Yes |
Keywords
- Circular dichroism
- Lipid-protein interaction
- Protein adsorption
- β-glycoprotein I
ASJC Scopus subject areas
- Biochemistry
- Molecular Biology
- Cell Biology