Two-dimensional crystallization of a bacterial surface protein on lipid vesicles under controlled conditions.
The solubilized surface protein of the Gram-negative bacterium Comamonas acidovorans was reconstituted on lipid vesicles by means of controlled dialysis. To this end, a multichamber dialysis apparatus was built which allows one to control the temperature and the dialysis rate, to apply various temperatures or buffer systems and sample conditions in a single experiment, and to monitor the turbidity of the sample by means of light scattering. The reconstitution conditions were optimized such that the surface protein formed two-dimensional crystals suitable for electron crystallography. The recrystallized surface protein arrays gave a resolution of approximately 1.3 nm in projection after correlation averaging of negatively stained preparations. The surface protein assembled into partially self-contained two-dimensional crystals which possess a strong shape-determining effect and formed cylinders and various cone-shaped vesicles. The development of the various vesicle forms is described in a model.
Paul
A
A
Max-Planck-Institut für Biochemie, Martinsried, Germany.
Engelhardt
H
H
Jakubowski
U
U
Baumeister
W
W
D001425:Bacterial Outer Membrane Proteins / Q000302:isolation & purification / Q000648:ultrastructure*; D003460:Crystallization; D004134:Dimyristoylphosphatidylcholine; D008027:Light; D008081:Liposomes; D008854:Microscopy, Electron; D008961:Models, Structural; D011487:Protein Conformation; D011549:Pseudomonas; D012542:Scattering, Radiation; D013816:Thermodynamics
D001425:Bacterial Outer Membrane Proteins; D008081:Liposomes; D004134:Dimyristoylphosphatidylcholine