title: Synchrotron radiation diffraction from two-dimensional protein crystals at the air/water interface.
abstract: Protein structure determination by classical x-ray crystallography requires three-dimensional crystals that are difficult to obtain for most proteins and especially for membrane proteins. An alternative is to grow two-dimensional (2D) crystals by adsorbing proteins to ligand-lipid monolayers at the surface of water. This confined geometry requires only small amounts of material and offers numerous advantages: self-assembly and ordering over micrometer scales is easier to obtain in two dimensions; although fully hydrated, the crystals are sufficiently rigid to be investigated by various techniques, such as electron crystallography or micromechanical measurements. Here we report structural studies, using grazing incidence synchrotron x-ray diffraction, of three different 2D protein crystals at the air-water interface, namely streptavidine, annexin V, and the transcription factor HupR. Using a set-up of high angular resolution, we observe narrow Bragg reflections showing long-range crystalline order in two dimensions. In the case of streptavidin the angular range of the observed diffraction corresponds to a resolution of 10 A in plane and 14 A normal to the plane. We show that this approach is complementary to electron crystallography but without the need for transfer of the monolayer onto a grid. Moreover, as the 2D crystals are accessible from the buffer solution, the formation and structure of protein complexes can be investigated in situ.
authors.affiliation: Laboratoire de Spectrométrie Physique, UMR Centre National de la Recherche Scientifique-Université J. Fourier, 38041 Grenoble, France.
authors.forename: P F
authors.initials: PF
authors.lastname: Lenne
authors.forename: B
authors.initials: B
authors.lastname: Berge
authors.forename: A
authors.initials: A
authors.lastname: Renault
authors.forename: C
authors.initials: C
authors.lastname: Zakri
authors.forename: C
authors.initials: C
authors.lastname: Vénien-Bryan
authors.forename: S
authors.initials: S
authors.lastname: Courty
authors.forename: F
authors.initials: F
authors.lastname: Balavoine
authors.forename: W
authors.initials: W
authors.lastname: Bergsma-Schutter
authors.forename: A
authors.initials: A
authors.lastname: Brisson
authors.forename: G
authors.initials: G
authors.lastname: Grübel
authors.forename: N
authors.initials: N
authors.lastname: Boudet
authors.forename: O
authors.initials: O
authors.lastname: Konovalov
authors.forename: J F
authors.initials: JF
authors.lastname: Legrand
mesh_terms: D000388:Air; D017304:Annexin A5 / Q000737:chemistry / Q000528:radiation effects; D001426:Bacterial Proteins / Q000737:chemistry / Q000528:radiation effects; D019921:Biotinylation; D002772:Cholera Toxin / Q000737:chemistry / Q000528:radiation effects; D018360:Crystallography, X-Ray / Q000379:methods; D004268:DNA-Binding Proteins; D005677:G(M1) Ganglioside / Q000737:chemistry; D005976:Glutaral / Q000737:chemistry; D008024:Ligands; D009532:Nickel / Q000737:chemistry; D010743:Phospholipids; D011506:Proteins / Q000737:chemistry* / Q000528:radiation effects; D019809:Streptavidin / Q000737:chemistry / Q000528:radiation effects; D017356:Synchrotrons; D014157:Transcription Factors / Q000737:chemistry / Q000528:radiation effects; D014867:Water / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D017304:Annexin A5; D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D008024:Ligands; D010743:Phospholipids; D011506:Proteins; D014157:Transcription Factors; D014867:Water; C070743:hupR1 protein, Rhodobacter capsulatus; D005677:G(M1) Ganglioside; D009532:Nickel; D002772:Cholera Toxin; D019809:Streptavidin; D005976:Glutaral