A leukotriene C4 synthase inhibitor with the backbone of 5-(5-methylene-4-oxo-4,5-dihydrothiazol-2-ylamino) isophthalic acid.

The cysteinyl leukotrienes (cys-LTs), leukotriene C4 (LTC4) and its metabolites, LTD4 and LTE4, are proinflammatory lipid mediators in asthma and other inflammatory diseases. They are generated through the 5-lipoxygenase/LTC4 synthase (LTC4S) pathway and act via at least two distinct G protein-coupled receptors. The inhibition of human LTC4S will make a simple way to treat the cys-LT relevant inflammatory diseases.

Seleno-detergent MAD phasing of leukotriene C4 synthase in complex with dodecyl-β-D-selenomaltoside.

Dodecyl-β-D-selenomaltoside (SeDDM) is a seleno-detergent with a β-glycosidic seleno-ether in place of the ether moiety in dodecyl-β-D-maltoside. Seleno-detergents are candidates for heavy-atom agents in experimental phasing of membrane proteins in protein crystallography. Crystals of a nuclear membrane-embedded enzyme, leukotriene C(4) synthase (LTC(4)S), in complex with SeDDM were prepared and a multiwavelength anomalous diffraction (MAD) experiment was performed.

The catalytic architecture of leukotriene C4 synthase with two arginine residues.

Leukotriene (LT) C(4) and its metabolites, LTD(4) and LTE(4), are involved in the pathobiology of bronchial asthma. LTC(4) synthase is the nuclear membrane-embedded enzyme responsible for LTC(4) biosynthesis, catalyzing the conjugation of two substrates that have considerably different water solubility; that amphipathic LTA(4) as a derivative of arachidonic acid and a water-soluble glutathione (GSH). A previous crystal structure revealed important details of GSH binding and implied a GSH activating function for Arg-104.

Dimeric crystal structure of rabbit L-gulonate 3-dehydrogenase/lambda-crystallin: insights into the catalytic mechanism.

l-Gulonate 3-dehydrogenase (GDH) is a bifunctional dimeric protein that functions not only as an NAD(+)-dependent enzyme in the uronate cycle but also as a taxon-specific lambda-crystallin in rabbit lens. Here we report the first crystal structure of GDH in both apo form and NADH-bound holo form. The GDH protomer consists of two structural domains: the N-terminal domain with a Rossmann fold and the C-terminal domain with a novel helical fold.

Structure of 3-oxoacyl-(acyl-carrier protein) synthase II from Thermus thermophilus HB8.

The beta-ketoacyl-(acyl carrier protein) synthases (beta-keto-ACP synthases; KAS) catalyse the addition of two-carbon units to the growing acyl chain during the elongation phase of fatty-acid synthesis. As key regulators of bacterial fatty-acid synthesis, they are promising targets for the development of new antibacterial agents. The crystal structure of 3-oxoacyl-ACP synthase II from Thermus thermophilus HB8 (TtKAS II) has been solved by molecular replacement and refined at 2.

Crystallization and preliminary X-ray crystallographic analysis of rabbit L-gulonate 3-dehydrogenase.

Rabbit L-gulonate 3-dehydrogenase was crystallized using the oil-microbatch method at 295 K. X-ray diffraction data were collected to 1.70 A resolution from a crystal at 100 K using synchrotron radiation.

Purification, crystallization and preliminary crystallographic analysis of the vacuole-type ATPase subunit E from Pyrococcus horikoshii OT3.

The vacuole-type ATPases in eukaryotic cells translocate protons across various biological membranes including the vacuolar membrane by consuming ATP molecules. The E subunit of the multisubunit complex V-ATPase from Pyrococcus horikoshii OT3, which has a molecular weight of 22.88 kDa, has been cloned, overexpressed in Escherichia coli, purified and crystallized by the microbatch method using PEG 4000 as a precipitant at 296 K.

Structure of ATP-dependent phosphoenolpyruvate carboxykinase from Thermus thermophilus HB8 showing the structural basis of induced fit and thermostability.

In order to understand the induced fit and the thermostabilization mechanisms of ATP-dependent phosphoenolpyruvate carboxykinase, the crystal structure of the enzyme from the extreme thermophile Thermus thermophilus HB8 (TtPEPCK) was determined and compared with those of orthologues of known structure from two mesophilic organisms. The protomer structures in these orthologues, which exhibit open/closed interdomain conformations, are similar. Isomorphous crystals of unliganded and ATP-bound TtPEPCK were obtained.

Degeneration of cholecystokinin-immunoreactive afferents to the VPL thalamus in a mouse model of Niemann-Pick disease type C.

Niemann-Pick disease type C (NP-C) is a progressive neurological disorder of lipid metabolism. The Balb/C npc1 mutant strain is a genetically authentic murine model of NPC, which reproduce the clinical and histologic features of human NP-C. In the present study, we show that cholecystokinin (CCK)-immunoreactive fibers in the thalamic VPL nuclei, which are densely distributed in controls, degenerate in NPC mice.

Axonal dystrophy of dorsal root ganglion sensory neurons in a mouse model of Niemann-Pick disease type C.

Niemann-Pick disease type C (NP-C) is a progressive and fatal neurological disorder characterized by intracellular accumulation of cholesterol and glycolipid. A Balb/c-npc1 mutant strain is a genetically authentic murine model of NP-C, and homozygous mice show progressive weight loss and tremor or ataxia until death at 12-14 weeks of age. Neuropathologically, this model is known to faithfully reproduce the cardinal histologic features of NP-C including neuronal storage, appearance of swollen axons (spheroids), and neuronal loss, although the cellular mechanisms of neural degeneration are largely unknown.

Crystal structure of purine nucleoside phosphorylase from Thermus thermophilus.

The purine nucleoside phosphorylase from Thermus thermophilus crystallized in space group P4(3)2(1)2 with the unit cell dimensions a = 131.9 A and c = 169.9 A and one biologically active hexamer in the asymmetric unit.

Crystallization and preliminary crystallographic analysis of 2-keto-3-deoxygluconate kinase from Thermus thermophilus.

2-Keto-3-deoxygluconate kinase (KDGK) catalyzes the phosphorylation of 2-keto-3-deoxygluconate (KDG) to 2-keto-3-deoxy-6-phosphogluconate. Two crystal forms of KDGK from Thermus thermophilus were obtained by vapour-diffusion and microbatch methods. Crystals in the form of triangular plates (TtKDGK-1) were obtained that belong to space group P3, with unit-cell parameters a = b = 145.

Gene amplification and mRNA and protein overexpression of c-erbB-2 (HER-2/neu) in human intrahepatic cholangiocarcinoma as detected by fluorescence in situ hybridization, in situ hybridization, and immunohistochemistry.

Background/aims: The human proto-oncogene c-erbB-2 (also called HER-2/neu) is located on chromosome 17q21-22. There have been no studies on gene amplification or mRNA expression of c-erbB-2 in human intrahepatic cholangiocarcinoma (CC) hitherto.

Methods: We investigated c-erbB-2 gene amplification by fluorescence in situ hybridization (FISH), c-erbB2 mRNA expression by ISH, and c-erbB-2 protein expression by immunohistochemistry in 22 archival cases of CC.