Trehalose embedding technique for high-resolution electron crystallography: application to structural study on bacteriorhodopsin.
Trehalose was compared with glucose in its use as an embedding medium for the preparation of two-dimensional crystals for electron crystallographic structure analysis. Purple membranes (two-dimensional crystals of bacteriorhodopsin) embedded in either sugar were studied in a 'partially hydrated' state as well as after 'drying' of the specimen. Diffraction patterns of the four conditions, all showing spots to a resolution better than 3.0 A, were analysed and merged. In the case of glucose embedded specimens, the merging R-factor obtained from the diffraction patterns of dried specimens was significantly better than the one obtained from partially hydrated specimens. In the case of trehalose embedding, the merging R-factor for partially hydrated specimens was significantly better than the dried one. The trehalose embedded, partially hydrated specimens gave the best merging R-factor in all four cases.
Hirai
T
T
International Institute for Advanced Research (IIAR), Matsushita Electric Industrial Co., Ltd, 3-4, Hikaridai, Seika, Soraku, Kyoto 619-0237, Japan.
Murata
K
K
Mitsuoka
K
K
Kimura
Y
Y
Fujiyoshi
Y
Y
D001436:Bacteriorhodopsins / Q000737:chemistry*; D018360:Crystallography, X-Ray / Q000379:methods*; D005947:Glucose; D019617:Halobacterium salinarum / Q000648:ultrastructure; D008854:Microscopy, Electron / Q000379:methods*; D016610:Tissue Embedding / Q000379:methods; D014199:Trehalose
D001436:Bacteriorhodopsins; D014199:Trehalose; D005947:Glucose