Increasing the diffraction limit and internal order of a membrane protein crystal by dehydration.
It is notoriously difficult to produce crystals of membrane proteins that diffract to sufficient resolution for structural studies by X-ray crystallography. Crystals of a prokaryotic CLC chloride channel that were initially unacceptable for structural analysis improved in both quality and diffraction limit by a process of dehydration. The loss of water decreased the dimensions of the unit cell axes by up to 25 A, improved the diffraction limit from 8.0 to 4.0 A, and decreased the mosaicity to values of approximately 1 degrees. Dehydration of integral membrane protein crystals should be one of the procedures included in the initial screening for appropriate crystals and as a method of improving the diffraction limits of existing crystals.
Kuo
Anling
A
Department of Biochemistry, Laboratory of Molecular Biophysics, University of Oxford, South Parks Road, Oxford OX1 3QU, UK.
Bowler
Matthew W
MW
Zimmer
Jochen
J
Antcliff
Jennifer F
JF
Doyle
Declan A
DA
D002462:Cell Membrane / Q000378:metabolism*; D018118:Chloride Channels / Q000737:chemistry; D018360:Crystallography, X-Ray / Q000379:methods*; D003681:Dehydration; D004926:Escherichia coli / Q000378:metabolism; D005656:Fungal Proteins / Q000648:ultrastructure; D013696:Temperature; D013997:Time Factors; D014961:X-Ray Diffraction / Q000379:methods*
D018118:Chloride Channels; D005656:Fungal Proteins