In meso Approaches to Membrane Protein Crystallization - Molecules: Nucleation, Aggregation and Crystallization - page 275

(a) (b)

Fig. 7. A depiction of the preparation of a bicelle probe for crystallization [modified
from Sanders et al . (1998)]. (a) A model CHAPSO-DMPC bicelle contains a reconsti-
tuted integral membrane protein (in green) [modified from Sanders et al . (1998)]. (b) The
right-hand side of the figure shows crystals grown by this method (Ishchenko et al .
unpublished).

BR crystals grown at room temperature are essentially identical to
twinned crystals previously obtained at 37 ° C: space group P2 1 (2.0 Å

resolution) with unit cell dimensions of a = 44.7 Å, b = 108.7 Å, c = 55.8 Å,

. The other room-temperature crystals are untwinned and
belong to space group C222 1 (2.2 Å resolution) with the following unit
cell dimensions: a

β = 113.6 °

128.2 Å.
After the first publication of this kind of crystallization, there
has been no further success with other membrane proteins. However,
very recently crystals of the human

= 44.7 Å, b = 102.5 Å, c =

β 2 -adrenergic G protein-coupled
receptor were grown in DMPC bicelles (Rasmussen et al ., 2007).
The structure was resolved to 3.5/3.7 Å resolution, which is consider-
ably lower than that obtained by protein crystallization in the cubic
phase (Cherezov et al ., 2007). However, taking into account the