title: Crystallization and preliminary X-ray diffraction analysis of the catalytic domain of recombinant human phosphodiesterase 3B.
abstract: The catalytic domain of human phosphodiesterase 3B has been cloned, expressed in Escherichia coli and purified in the presence of the PDE3 inhibitors IBMX (3-isobutylmethylxanthine) or MERCK1 by affinity chromatography. Initial screening of crystallization conditions for these complexes in the hanging-drop vapor-diffusion mode resulted in three different crystal forms, all characterized by quite large unit-cell parameters, elevated solvent content and poor diffraction quality. Subsequent optimization of these conditions led to crystals that diffract to 2.4 A and belong to space group C2, with unit-cell parameters a = 146.7, b = 121.5, c = 126.3 A, beta = 100.6 degrees. Rotation-function analysis indicates that the asymmetric unit contains four copies of the monomeric enzyme, corresponding to a solvent content of 64%. To solve the structure of the PDE3B catalytic domain, molecular replacement as well as multiple isomorphous replacement methods are currently being utilized.
authors.affiliation: Department of Medicinal Chemistry, Merck and Co., Rahway, NJ 07065, USA.
authors.forename: Sangita B
authors.initials: SB
authors.lastname: Patel
authors.forename: Jeffrey P
authors.initials: JP
authors.lastname: Varnerin
authors.forename: Michael R
authors.initials: MR
authors.lastname: Tota
authors.forename: Scott D
authors.initials: SD
authors.lastname: Edmondson
authors.forename: Emma R
authors.initials: ER
authors.lastname: Parmee
authors.forename: Joseph W
authors.initials: JW
authors.lastname: Becker
authors.forename: Giovanna
authors.initials: G
authors.lastname: Scapin
mesh_terms: D015056:1-Methyl-3-isobutylxanthine / Q000737:chemistry; D015105:3',5'-Cyclic-AMP Phosphodiesterases / Q000737:chemistry*; D020134:Catalytic Domain; D002846:Chromatography, Affinity; D003460:Crystallization; D018360:Crystallography, X-Ray; D054684:Cyclic Nucleotide Phosphodiesterases, Type 3; D006801:Humans; D010726:Phosphodiesterase Inhibitors / Q000737:chemistry; D011994:Recombinant Proteins / Q000737:chemistry
chemical_list: D010726:Phosphodiesterase Inhibitors; D011994:Recombinant Proteins; D015105:3',5'-Cyclic-AMP Phosphodiesterases; D054684:Cyclic Nucleotide Phosphodiesterases, Type 3; C517291:PDE3B protein, human; D015056:1-Methyl-3-isobutylxanthine