1by6
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PEPTIDE OF HUMAN APOLIPOPROTEIN C-II
OverviewOverview
We have studied the three-dimensional structure of a biologically active, peptide of apolipoprotein C-II (apoC-II) in the presence of lipid mimetics, by CD and NMR spectroscopy. This peptide, corresponding to residues 44-79, of apoC-II, has been shown to reverse the symptoms of genetic apoC-II, deficiency in a human subject. A comparison of alpha-proton secondary, shifts and CD spectroscopic data indicates that the structure of, apoC-II(44-79) is similar in the presence of dodecylphosphocholine and, sodium dodecyl sulfate. The three-dimensional structure of apoC-II(44-79), in the presence of sodium dodecyl sulfate, determined by relaxation matrix, calculations, contains two amphipathic helical domains formed by residues, 50-58 and 67-75, separated by a non-helical linker centered at Tyr63. The, C-terminal helix is terminated by a loop formed by residues 76-79. The, C-terminal helix is better defined and has a larger hydrophobic face than, the N-terminal helix, which leads us to propose that the C-terminal helix, together with the non-helical Ile66 constitute the primary lipid binding, domain of apoC-II(44-79). Based on our structure we suggest a new, mechanism of lipoprotein lipase activation in which both helices of, apoC-II(44-79) remain lipid bound, while the seven-residue interhelical, linker extends away from the lipid surface in order to project Tyr63 into, the apoC-II binding site of lipoprotein lipase.
DiseaseDisease
Known disease associated with this structure: Hyperlipoproteinemia, type Ib OMIM:[608083]
About this StructureAbout this Structure
1BY6 is a Single protein structure of sequence from [1]. Full crystallographic information is available from OCA.
ReferenceReference
Structure of a biologically active fragment of human serum apolipoprotein C-II in the presence of sodium dodecyl sulfate and dodecylphosphocholine., Storjohann R, Rozek A, Sparrow JT, Cushley RJ, Biochim Biophys Acta. 2000 Jul 19;1486(2-3):253-64. PMID:10903476
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