title: The antifolate trimetrexate: observation of the enzyme-binding conformation.
abstract: The crystal structure of the title compound contains four 2, 4-diamino-5-methyl-6-[(3,4,5-trimethoxyanilino)methyl]quinazoline molecules, two dimethyl sulfoxide molecules and three water molecules in the asymmetric unit, i.e. 4C(19)H(23)N(5)O(3).-2C(2)H(6)OS.3H(2)O. All four quinazoline molecules adopt trans,-gauche conformations. An extensive hydrogen-bond network involving N. N base-pairing interactions, as well as the dimethyl sulfoxide and water molecules, stabilizes the crystal structure.
authors.affiliation: Department of Biochemistry, University of Toronto, Medical Sciences Building, Toronto, Canada M5S 1A8. andrew.hempel@utoronto.ca.
authors.forename: A
authors.initials: A
authors.lastname: Hempel
authors.forename: N
authors.initials: N
authors.lastname: Camerman
authors.forename: D
authors.initials: D
authors.lastname: Mastropaolo
authors.forename: A
authors.initials: A
authors.lastname: Camerman
mesh_terms: D018360:Crystallography, X-Ray; D005493:Folic Acid Antagonists / Q000737:chemistry*; D006860:Hydrogen Bonding; D007780:Lacticaseibacillus casei / Q000201:enzymology; D008958:Models, Molecular; D008968:Molecular Conformation; D011485:Protein Binding; D013762:Tetrahydrofolate Dehydrogenase / Q000378:metabolism*; D016597:Trimetrexate / Q000737:chemistry*
chemical_list: D005493:Folic Acid Antagonists; D013762:Tetrahydrofolate Dehydrogenase; D016597:Trimetrexate