Crystallization and preliminary X-ray diffraction analysis of apolipoprotein E-containing lipoprotein particles.
High-resolution structural information is available for several soluble plasma apolipoproteins (apos) in a lipid-free state. However, this information provides limited insight into structure-function relationships, as this class of proteins primarily performs its functions of lipid transport and modulation of lipid metabolism in a lipid-bound state on lipoprotein particles. Here, the possibility of generating homogeneous lipoprotein particles that could be crystallized was explored, opening the possibility of obtaining high-resolution structural information by X-ray crystallography. To test this possibility, apoE4 complexed with the phospholipid dipalmitoylphosphatidylcholine was chosen. Uniform particles containing 50% lipid and 50% apoE4 were obtained and crystallized using the hanging-drop method. Two crystal forms diffract to beyond 8 A resolution.
Newhouse
Yvonne
Y
Gladstone Institutes of Cardiovascular and Neurological Disease, University of California, San Francisco, CA 94158, USA.
Peters-Libeu
Clare
C
Weisgraber
Karl H
KH
D015060:1,2-Dipalmitoylphosphatidylcholine / Q000737:chemistry; D001057:Apolipoproteins E / Q000737:chemistry*; D003432:Cross-Linking Reagents / Q000494:pharmacology; D003460:Crystallization / Q000379:methods; D018360:Crystallography, X-Ray; D004591:Electrophoresis, Polyacrylamide Gel; D005347:Fibroblasts / Q000378:metabolism; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008055:Lipids / Q000737:chemistry; D008074:Lipoproteins / Q000737:chemistry*; D008854:Microscopy, Electron; D010743:Phospholipids / Q000737:chemistry; D011485:Protein Binding; D011487:Protein Conformation; D011973:Receptors, LDL / Q000737:chemistry; D013696:Temperature; D014961:X-Ray Diffraction / Q000379:methods
D001057:Apolipoproteins E; D003432:Cross-Linking Reagents; D008055:Lipids; D008074:Lipoproteins; D010743:Phospholipids; D011973:Receptors, LDL; D015060:1,2-Dipalmitoylphosphatidylcholine