+1 Recommend
0 collections
      • Record: found
      • Abstract: found
      • Article: not found

      N-terminal domain of apolipoprotein B has structural homology to lipovitellin and microsomal triglyceride transfer protein: a "lipid pocket" model for self-assembly of apob-containing lipoprotein particles.

      Journal of Lipid Research
      Animals, Apolipoproteins B, chemistry, metabolism, Carrier Proteins, Computer Simulation, Egg Proteins, Egg Proteins, Dietary, Humans, Lipoproteins, Models, Biological, Models, Chemical, Models, Molecular, Protein Structure, Secondary, Reproducibility of Results, Sequence Alignment, methods, Species Specificity

      Read this article at

          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.


          The process of assembly of apolipoprotein (apo) B-containing lipoprotein particles occurs co-translationally after disulfide-dependent folding of the N-terminal domain of apoB but the mechanism is not understood. During a recent database search for protein sequences that contained similar amphipathic beta strands to apoB-100, four vitellogenins, the precursor form of lipovitellin, an egg yolk lipoprotein, from chicken, frog, lamprey, and C. elegans appeared on the list of candidate proteins. The X-ray crystal structure of lamprey lipovitellin is known to contain a "lipid pocket" lined by antiparallel amphipathic beta sheets. Here we report that the first 1000 residues of human apoB-100 (the alpha(1) domain plus the first 200 residues of the beta(1) domain) have sequence and amphipathic motif homologies to the lipid-binding pocket of lamprey lipovitellin. We also show that most of the alpha(1) domain of human apoB-100 has sequence and amphipathic motif homologies to human microsomal triglyceride transfer protein (MTP), a protein required for assembly of apoB-containing lipoproteins. Based upon these results, we suggest that an LV-like "proteolipid" intermediate containing a "lipid pocket" is formed by the N-terminal portion of apoB alone or, more likely, as a complex with MTP. This intermediate produces a lipid nidus required for assembly of apoB-containing lipoprotein particles; pocket expansion through the addition of amphipathic beta strands from the beta(1) domain of apoB results in the formation of a progressively larger high density lipoprotein (HDL)-like, then very low density lipoprotein (VLDL)-like, spheroidal lipoprotein particle.

          Related collections

          Author and article information


          Comment on this article