title: Roles of hydration water molecules in molecular packing of the killer toxin from Pichia farinosa in its crystalline state investigated by cryogenic X-ray crystallography.
abstract: The hydration structures around the killer toxin from Pichia farinosa were investigated by cryogenic X-ray crystallography. In particular, those contributing to the molecular association and the crystal contacts were analyzed with respect to the geometry and the networks of hydrogen bonds. The hydration water molecules attached on the surface so as to make up the surface shape in the contact complementary and mediated the intermolecular interactions through the networks of hydrogen bonds. Careful inspection of the contact area led to a proposal as to the molecular association mode of the toxin to determine the biological function in cells. In addition, the water-associated protein-protein interactions were approximated well by a simple theoretical equation on the solvation force expected in confined geometry. The present analysis may provide a way to analyze the crystal contact and molecular recognition in macromolecules in aqueous solution.
authors.affiliation: Precursory Research for Embryonic Science and Technology, Japan Science and Technology Corporation and Institute of Molecular and Cellular Biosciences, The University of Tokyo, Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan. nakasako@iam.u-tokyo.ac.jp
authors.forename: Masayoshi
authors.initials: M
authors.lastname: Nakasako
authors.forename: Fumihiko
authors.initials: F
authors.lastname: Tsuchiya
authors.forename: Yoji
authors.initials: Y
authors.lastname: Arata
mesh_terms: D003460:Crystallization; D018360:Crystallography, X-Ray; D019281:Dimerization; D006860:Hydrogen Bonding; D008958:Models, Molecular; D015394:Molecular Structure; D009183:Mycotoxins / Q000737:chemistry* / Q000378:metabolism; D010843:Pichia / Q000737:chemistry* / Q000378:metabolism; D011487:Protein Conformation; D013696:Temperature; D014867:Water / Q000737:chemistry* / Q000378:metabolism
chemical_list: D009183:Mycotoxins; D014867:Water