title: An improved strategy for the crystallization of Leishmania mexicana pyruvate kinase.
abstract: The inclusion of novel small molecules in crystallization experiments has provided very encouraging results and this method is now emerging as a promising alternative strategy for crystallizing 'problematic' biological macromolecules. These small molecules have the ability to promote lattice formation through stabilizing intermolecular interactions in protein crystals. Here, the use of 1,3,6,8-pyrenetetrasulfonic acid (PTS), which provides a helpful intermolecular bridge between Leishmania mexicana PYK (LmPYK) macromolecules in the crystal, is reported, resulting in the rapid formation of a more stable crystal lattice at neutral pH and greatly improved X-ray diffraction results. The refined structure of the LmPYK-PTS complex revealed the negatively charged PTS molecule to be stacked between positively charged (surface-exposed) arginine side chains from neighbouring LmPYK molecules in the crystal lattice.
authors.affiliation: Structural Biochemistry Group, Institute of Structural and Molecular Biology, The University of Edinburgh, Michael Swann Building, The King's Buildings, Mayfield Road, Edinburgh EH9 3JR, Scotland.
authors.forename: Hugh P
authors.initials: HP
authors.lastname: Morgan
authors.forename: Iain W
authors.initials: IW
authors.lastname: McNae
authors.forename: Kun-Yi
authors.initials: KY
authors.lastname: Hsin
authors.forename: Paul A M
authors.initials: PA
authors.lastname: Michels
authors.forename: Linda A
authors.initials: LA
authors.lastname: Fothergill-Gilmore
authors.forename: Malcolm D
authors.initials: MD
authors.lastname: Walkinshaw
mesh_terms: D018360:Crystallography, X-Ray; D007894:Leishmania mexicana / Q000201:enzymology*; D008958:Models, Molecular; D020836:Protein Structure, Quaternary; D011770:Pyruvate Kinase / Q000737:chemistry* / Q000378:metabolism; D013379:Substrate Specificity; D013451:Sulfonic Acids / Q000737:chemistry / Q000378:metabolism
chemical_list: D013451:Sulfonic Acids; D011770:Pyruvate Kinase