Stoichiometry of reconstituted high-density lipoproteins in the hydrated state determined by photon antibunching

Biophys J. 2011 Aug 17;101(4):970-5. doi: 10.1016/j.bpj.2011.06.060.

Abstract

Apolipoprotein A-I plays a central role in the solution structure of high-density lipoproteins. Determining the stoichiometry of lipid-bound apo A-I in the hydrated state is therefore fundamental to understanding how high-density lipoproteins form and function. Here, we use the quantum optical phenomenon of photon antibunching to determine the number of apo A-I molecules bound to discoidal lipoproteins and compare this with values obtained by photon-counting histogram analysis. Both the photon antibunching and photon-counting analyses show that reconstituted high-density lipoprotein particles contain two apo A-I molecules, which is in agreement with the commonly accepted double-belt model.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Apolipoprotein A-I / chemistry
  • Apolipoprotein A-I / metabolism
  • Biophysics / methods*
  • Lipoproteins, HDL / chemistry*
  • Lipoproteins, HDL / metabolism
  • Photons*
  • Protein Conformation
  • Spectrometry, Fluorescence
  • Water / chemistry*

Substances

  • Apolipoprotein A-I
  • Lipoproteins, HDL
  • Water