title: Apolipoprotein structural organization in high density lipoproteins: belts, bundles, hinges and hairpins.
abstract: OBJECTIVE
  To summarize recent advances towards an understanding of the three-dimensional structures of the apolipoprotein components of HDL with a specific focus on high resolution models of apolipoprotein A-I.
  
  
  RESULTS
  Since the primary sequence was first reported, various models have been advanced for the structure of apolipoprotein A-I, the major protein constituent of HDL, in its lipid-free and lipid-bound forms. Unfortunately, the generation of experimental data capable of distinguishing among the competing models has lagged far behind. However, recent experimental strategies, including X-ray crystallography, applications of resonance energy transfer and mass spectrometry, have combined with sophisticated theoretical approaches to develop three-dimensional structural models of apolipoprotein A-I with previously unavailable resolution.
  
  
  CONCLUSIONS
  The recent synergy of sophisticated computer modeling techniques with hard experimental data has generated new models for apolipoprotein A-I in certain subclasses of HDL produced in vitro. The challenge now is to adapt and test these models in the more complex forms of HDL isolated directly from human plasma.
authors.affiliation: Department of Pathology and Laboratory Medicine, University of Cincinnati, Cincinnati, Ohio 45237-0507, USA. sean.davidson@uc.edu
authors.forename: W Sean
authors.initials: WS
authors.lastname: Davidson
authors.forename: R A Gangani D
authors.initials: RA
authors.lastname: Silva
mesh_terms: D016632:Apolipoprotein A-I / Q000737:chemistry* / Q000502:physiology*; D008076:Cholesterol, HDL / Q000737:chemistry*; D018360:Crystallography, X-Ray; D006801:Humans; D008956:Models, Chemical; D011487:Protein Conformation
chemical_list: D016632:Apolipoprotein A-I; D008076:Cholesterol, HDL