Melted monoolein was thoroughly mixed in a ratio of 3:2 (v/v) with 0.1M HEPES, pH 7.5, 0.1 % LDAO until a viscous, transparent LCP was obtained. The formed phase was then transferred into a glass vial and sponge-phase-inducing solution (1:4 ratio) was added containing 16% Jeffamine M-600, 1M HEPES pH 7.9, 0.7 M Ammonium sulphate, 2.5% 1,2,3-Heptanetriol, which swell the cubic phase to sponge phase. After phase separation overnight, the upper phase (sponge phase) was harvested.
Crystals were grown using batch crystallization in the lipidic-sponge phase. Equal amount of sponge phase and protein were mixed with 2/5 (v/v) of 1.2 M Tris-sodium citrate and allowed to incubate for several weeks.