1BY6

Peptide of human apolipoprotein C-II

Summary for 1BY6

• Entry DOI: 10.2210/pdb1by6/pdb
• Descriptor: APOLIPOPROTEIN C-II (1 entity in total)
• Functional Keywords: apolipoprotein, amphipathic helix, lipid association, lpl activation, signaling protein
• Biological source: HOMO SAPIENS (HUMAN)
• Cellular location: Secreted : P02655
• Total number of polymer chains: 1
• Total formula weight: 3971.44

Authors

Storjohann, R.,Rozek, A.,Sparrow, J.T.,Cushley, R.J. (deposition date: 1999-12-03, release date: 2000-11-15, Last modification date: 2024-04-10)

Primary citation

Storjohann, R.,Rozek, A.,Sparrow, J.T.,Cushley, R.J.
Structure of a biologically active fragment of human serum apolipoprotein C-II in the presence of sodium dodecyl sulfate and dodecylphosphocholine.
Biochim.Biophys.Acta, 1486:253-264, 2000

PubMed Abstract: 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.

PubMed: 10903476
DOI: 10.1016/S1388-1981(00)00062-7

Experimental method

SOLUTION NMR