The location of bound lipid in the lipovitellin complex.

The location of the bound lipid in the soluble lipoprotein lipovitellin has been determined by neutron crystallographic techniques. With the use of the contrast variation method, whereby the crystals are soaked in different H2O-D2O mixtures, the lipid has been found to occupy a large cavity in the protein whose structure had previously been determined by x-ray crystallography. The lipid appears to be bound in the form of a bilayer with the major protein-lipid interactions being hydrophobic and with the lipid headgroups projecting into the bulk solvent and into a solvent-filled space in the cavity.