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Figure 1.
Figure 1. Bicelle crystallization method. (a) Outline of
the method. (b) Crystals of bR grown from bicelle forming
lipid/detergent mixture. Purple membrane was purified as
described by Oesterhelt & Steckenius.[29] Purple membrane was
suspended in water to a bR concentration of  vert,
similar 10 mg/ml and was mixed in a 4:1 ratio with a 40% (3:1)
DMPC/Chapso bicellar solution, making a vert,
similar 8.0 mg/ml bR/8% bicelles mixture. Reconstitution and
homogenization of the protein into the bicelles was achieved
simply by repeated pipeting of the solution. Crystals were grown
using the hanging, or sitting drop method and all solutions were
kept on ice prior to mixing to keep the bicelle mixtures fluid.
The crystallization drops contained 6 µl of
protein/bicelle solution with 2.5 µl of well solution and
1 µl of 2.5% b-octylglucoside (OG) solution. The well
solution contained 3.2 M NaPO[4] (pH 3.5). The crystal trays
were then placed in a 37°C incubator to allow the bicelles
to gel. Diamond-shaped crystals grew within a few days to two
weeks. The addition of OG was not required for crystal growth;
however, larger crystals were obtained in its presence.
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