Age and Sex in the Development of Hepatic Encephalopathy: Role of Alcohol.

Hepatic encephalopathy (HE) is a neurological condition linked to liver failure. Acute HE (Type A) occurs with acute liver failure, while chronic HE (Type C) is tied to cirrhosis and portal hypertension. HE treatments lag due to gaps in understanding its development by gender and age. We studied how sex and age impact HE and its severity with combined liver toxins. Our findings indicate that drug-induced (thioacetamide, TAA) brain edema was more severe in aged males than in young males or young/aged female rats. However, adding alcohol (ethanol, EtOH) worsens TAA's brain edema in both young and aged females, with females experiencing a more severe effect than males. These patterns also apply to Type A HE induced by azoxymethane (AZO) in mice. Similarly, TAA-induced behavioral deficits in Type C HE were milder in young and aged females than in males. Conversely, EtOH and TAA in young/aged males led to severe brain edema and fatality without noticeable behavioral changes. TAA metabolism was slower in aged males than in young or middle-aged rats. When TAA-treated aged male rats received EtOH, there was a slow and sustained plasma level of thioacetamide sulfoxide (TASO). This suggests that with EtOH, TAA-induced HE is more severe in aged males. TAA metabolism was similar in young, middle-aged, and aged female rats. However, with EtOH, young and aged females experience more severe drug-induced HE as compared to middle-aged adult rats. These findings strongly suggest that gender and age play a role in the severity of HE development and that the presence of one or more liver toxins may aggravate the severity of the disease progression.

Crystal structure of XoLAP, a leucine aminopeptidase, from Xanthomonas oryzae pv. oryzae.

Aminopeptidases are metalloproteinases that degrade N-terminal residues from protein and play important roles in cell growth and development by controlling cell homeostasis and protein maturation. We determined the crystal structure of XoLAP, a leucyl aminopeptidase, at 2.6 Å resolution from Xanthomonas oryzae pv. oryzae, causing the destructive rice disease of bacterial blight. It is the first crystal structure of aminopeptidase from phytopathogens as a drug target. XoLAP existed as a hexamer and the monomer structure consisted of an N-terminal cap domain and a C-terminal peptidase domain with two divalent zinc ions. XoLAP structure was compared with BlLAP and EcLAP (EcPepA) structures. Based on the structural comparison, the molecular model of XoLAP in complex with the natural aminopeptidase inhibitor of microginin FR1 was proposed. The model structure will be useful to develop a novel antibacterial drug against Xoo.

(3-Ethyl-6,7-dimeth-oxy-naphthalen-1-yl)(phen-yl)methanone.

The asymetric unit of the title mol-ecule, C(21)H(20)O(3), contains two crystallographically independent mol-ecules, A and B, which differ in the orientation of the ethyl group substituted on the naphthalene system; the dihedral angles between the ethyl group and the naphthalene system are 7.4 (3) and 68.1 (3)°, respectively, for mol-ecules A and B. The dihedral angles between the benzoyl and naphthalene groups are 64.7 (7) and 69.4 (8)°, respectively, for mol-ecules A and B. The crystal structure features four aromatic π-π stacking interactions [centroid-centroid distances = 4.181 (1), 3.891 (1), 4.423 (1) and 4.249 (1) Å].

Cloning, expression, crystallization and preliminary X-ray crystallographic analysis of aspartyl aminopeptidase from the apeB gene of Pseudomonas aeruginosa.

Aminopeptidases (APs) are a group of exopeptidases that catalyze the removal of amino acids from the N-termini of proteins and peptides. The APs are ubiquitous in nature and are of critical biological and medical importance because of their key role in protein degradation. Pseudomonas aeruginosa aspartyl aminopeptidase (PaAAP), which is encoded by the apeB gene, was expressed in Escherichia coli, purified and crystallized using the microbatch method. A preliminary structural study has been performed using the X-ray crystallographic method. The PaAAP crystal diffracted to 2.0 Å resolution and belonged to the rhombohedral space group H3, with unit-cell parameters a = b = 133.6, c = 321.2. The unit-cell volume of the crystal is compatible with the presence of four monomers in the asymmetric unit, with a corresponding Matthews coefficient V(M) of 2.95 Å(3) Da(-1) and a solvent content of 58.3%.

1'-Methyl-4'-phenyl-2''-sulfanylidene-dispiro-[indoline-3,2'-pyrrolidine-3',5''-1,3-thia-zolidine]-2,4''-dione.

The title compound, C(20)H(17)N(3)O(2)S(2), crystallizes with two mol-ecules in the asymmetric unit. The pyrrolo-dine rings have envelope conformations in both mol-ecules, the N atoms deviating by 0.574 (3) and 0.612 (2) Šfrom the mean planes through the other ring atoms. The 1'-methyl and 4'-phenyl groups on the pyrrolidine rings are substituted in equatorial positions. In the crystal, mol-ecules are linked into a three-dimensional network by N-H⋯O, N-H⋯N and C-H⋯O and N-H⋯π hydrogen bonds.

(Z)-2-[(4-Methyl-phen-yl)sulfon-yl]-1,2-diphenyl-ethene-selenol.

In the title compound, C(21)H(18)O(2)SSe, the dihedral angle between the cis phenyl rings is 64.3 (1)° and those between the toluene and the phenyl rings are 21.1 (2) and 72.0 (1)°, respectively. An intra-molecular Se-H⋯O hydrogen bond occurs. In the crystal, mol-ecules are connected by C-H⋯O hydrogen bonds and weak C-H⋯π inter-actions help to consolidate the crystal packing.

4-Amino-3-(4-chloro-phen-yl)-1H-1,2,4-triazole-5(4H)-thione.

In the title compound, C(8)H(7)ClN(4)S, the benzene ring is statistically disordered over two conformations rotated about the Cl-C⋯C-C axis, which subtend dihedral angles of 24.7 (3) and 9.9 (2) ° with respect to the triazole ring. An intra-molecular C-H⋯N close contact occurs. In the crystal, N-H⋯N and N-H⋯S hydrogen bonds link the mol-ecules into (001) sheets: R(2) (2)(8) and R(2) (2)(10) graph-set motifs result. Weak C-H⋯N hydrogen bonds and aromatic π-π stacking inter-actions [shortest centroid-centroid separation = 3.681 (7) Å] complete the structure.

Crystal structure of malonyl CoA-Acyl carrier protein transacylase from Xanthomanous oryzae pv. oryzae and its proposed binding with ACP.

Xanthomonas oryzae pv. oryzae (Xoo) is a plant bacterial pathogen that causes bacterial blight (BB) disease, resulting in serious production losses of rice. The crystal structure of malonyl CoA-acyl carrier protein transacylase (XoMCAT), encoded by the gene fabD (Xoo0880) from Xoo, was determined at 2.3 Å resolution in complex with N-cyclohexyl-2-aminoethansulfonic acid. Malonyl CoA-acyl carrier protein transacylase transfers malonyl group from malonyl CoA to acyl carrier protein (ACP). The transacylation step is essential in fatty acid synthesis. Based on the rationale, XoMCAT has been considered as a target for antibacterial agents against BB. Protein-protein interaction between XoMCAT and ACP was also extensively investigated using computational docking, and the proposed model revealed that ACP bound to the cleft between two XoMCAT subdomains.

1-Benzoyl-4-(4-methyl-phen-yl)phthal-azine.

In the title mol-ecule, C(22)H(16)N(2)O, the tolyl and benzoyl rings make dihedral angles 50.2 (5) and 56.4 (5)°, respectively, with the phthalazine ring system while the dihedral angle between the tolyl and benzoyl rings is 0.70 (4)°. The crystal structure is stabilized by inter-molecular C-H⋯O and C-H⋯N hydrogen bonds, as well as weak C-H⋯π inter-actions.

2,4-Diamino-5-(4-chloro-phen-yl)-6-ethyl-pyrimidin-1-ium 2-acet-amido-benzoate.

The title compound, C(12)H(14)ClN(4) (+)·C(9)H(8)NO(3) (-), is a salt with a 1:1 ratio of cation and anion components inter-acting with each other forming an R(2) (2)(8) ring motif. The crystal structure is stabilized by hydrogen bonds (N-H⋯O) involving two different eight-membered rings. One of them is formed between the pyrimidine ring (donor) and the carboxylate group (acceptor) from the benzoate, whereas the other ring is formed by N-H⋯O interactions, which help to form a dimer between two symmetry-related salts in the unit cell. In addition, an intramolecular C-H⋯N and intermolecular C-H⋯Cl interactions help to control the molecules in the unit-cell packing.

2,4-Diamino-5-(4-chloro-phen-yl)-6-ethyl-pyrimidin-1-ium 2-propanamido-benzoate.

In the title salt, C(12)H(14)ClN(4) (+)·C(10)H(10)NO(3) (-), zwitterionic N-H⋯O inter-actions form an R(2) (2)(8) ring. The crystal structure is stabilized by N-H⋯O and N-H⋯N hydrogen bonds involving two different eight-membered rings. An N-H⋯O inter-action occurs between the pyrimidine ring (donor) and carboxyl-ate group (acceptor) while the other ring is formed by N-H⋯N inter-actions, which form a dimer between two symmetry-related salts. An intra-molecular N-H⋯O hydrogen bond forms a six-membered ring in the benzoate. Inter-molecular C-H⋯O inter-actions are also observed.

3-Nitroso-2,4,6,8-tetra-phenyl-3,7-diaza-bicyclo-[3.3.1]nonan-9-one.

In the title compound, C(31)H(27)N(3)O(2), the two piperidine rings fused to each other each adopt a slightly distorted chair conformation. The phenyl rings on the N-unsubstituted piperidine ring occupy an equatorial position, while those on the N-nitroso-substituted piperidine ring are in axial positions. The NO group is approximately coplanar with the piperidine ring with a maximum deviation of 0.048 (4) Å. The dihedral angles between the mean planes of the axially and equatorially oriented phenyl rings are 27.7 (1) and 31.9 (1)°, respectively. Mol-ecular packing is stabilized by weak inter-molecular C-H⋯O and C-H⋯π inter-actions.

Ethyl 3-methyl-2,6-diphenyl-piperidine-1-carboxyl-ate.

In the title compound, C(21)H(25)NO(2), the piperidine ring adopts a twisted boat conformation characterized by puckering parameters θ = 89.5 (1) and ϕ = 257.5 (2)°. The phenyl groups are located in equatorial and axial positions on the central piperidine ring, while the methyl group is in an equatorial position. The dihedral angle between the phenyl rings is 49.8 (1)°. An intra-molecular C-H⋯O inter-action occurs. The crystal structure features weak inter-molecular C-H⋯O inter-actions and a stabilizing inter-molecular C-H⋯π contact involving the axial phenyl ring.

Cloning, expression, crystallization and preliminary X-ray crystallographic analysis of the co-chaperonin XoGroES from Xanthomonas oryzae pv. oryzae.

Bacterial blight (BB), a devastating disease caused by Xanthomonas oryzae pv. oryzae (Xoo), causes serious production losses of rice in Asian countries. Protein misfolding may interfere with the function of proteins in all living cells and must be prevented to avoid cellular disaster. All cells naturally contain molecular chaperones that assist the unfolded proteins in folding into the native structure. One of the well characterized chaperone complexes is GroEL-GroES. GroEL, which consists of two chambers, captures misfolded proteins and refolds them. GroES is a co-chaperonin protein that assists the GroEL protein as a lid that temporarily closes the chamber during the folding process. Xoo4289, the GroES gene from Xoo, was cloned and expressed for X-ray crystallographic study. The purified protein (XoGroES) was crystallized using the hanging-drop vapour-diffusion method and a crystal diffracted to 2.0 Šresolution. The crystal belonged to the hexagonal space group P6(1), with unit-cell parameters a=64.4, c=36.5 Å. The crystal contains a single molecule in the asymmetric unit, with a corresponding VM of 2.05 Å3 Da(-1) and a solvent content of 39.9%.

4-({(E)-[2-(But-3-en-1-yl)-1-(prop-2-en-1-yl)-4-sulfanyl-1H-imidazol-5-yl]methyl-idene}amino)-3-phenyl-1H-1,2,4-triazole-5(4H)-thione.

In the title compound, C(19)H(20)N(6)S(2), the dihedral angle between the phenyl and triazole rings is 24.1 (2)° while the dihedral angles between the imidazole ring and the triazole and phenyl rings are 39.9 (2) and 55.3 (2)°, respectively. The crystal structure is stabilized by inter-molecular N-H⋯N hydrogen bonds which form chains along [10[Formula: see text]].

Crystallization and preliminary X-ray crystallographic analysis of L-rhamnose isomerase with a novel high thermostability from Bacillus halodurans.

L-Rhamnose isomerases catalyze isomerization between L-rhamnose (6-deoxy-L-mannose) and L-rhamnulose (6-deoxy-L-fructose), which is the first step in rhamnose catabolism. L-Rhamnose isomerase from Bacillus halodurans ATCC BAA-125 (BHRI) exhibits interesting characteristics such as high thermostability and selective substrate specificity. BHRI fused with an HHHHHH sequence was purified and crystallized in order to elucidate the molecular basis of its unique enzymatic properties. The crystals were grown by the hanging-drop vapour-diffusion method and belonged to the monoclinic space group P2(1), with unit-cell parameters a = 83.2, b = 164.9, c = 92.0 A, beta = 116.0 degrees . Diffraction data were collected to 2.5 A resolution. According to a Matthews coefficient calculation, there are four monomers in the asymmetric unit with a V(M) of 3.0 A(3) Da(-1) and a solvent content of 59.3%. The initial structure of BHRI has been determined by the molecular-replacement method.

Overexpression, crystallization and preliminary X-ray crystallographic analysis of D-ribose-5-phosphate isomerase from Clostridium thermocellum.

Rare sugars are used for many industrial and medical purposes and are produced by the interconversion between aldoses and ketoses catalyzed by sugar and sugar-phosphate isomerases. Recently, Clostridium thermocellum d-ribose-5-phosphate isomerase (CTRPI), an aldose-ketose isomerase, was cloned in order to synthesize d-allose and its substrate specificity was further characterized for industrial usage. CTRPI has a novel substrate specificity that differs from those of other isomerases, which have broad substrate specificities. CTRPI prefers aldose substrates such as l-talose, d-ribose and d-allose. CTRPI was purified and crystallized in order to determine its three-dimensional structure and thus to elucidate its enzymatic reaction mechanism and understand its substrate specificity. The crystal belonged to the trigonal space group P3(2)21, with unit-cell parameters a = b = 69.5, c = 154.4 angstrom, and diffracted to 1.9 angstrom resolution. According to Matthews coefficient calculations, the crystallographic structure consists of a dimer in the asymmetric unit, with a V(M) of 3.2 angstrom(3) Da(-1) and a solvent content of 61.7%.

Cloning, expression, crystallization and preliminary X-ray crystallographic analysis of leucine aminopeptidase (LAP) from the pepA gene of Xanthomonas oryzae pv. oryzae.

Xanthomonas oryzae pv. oryzae (Xoo) causes the serious disease bacterial blight in rice. The pepA (Xoo0834) gene from Xoo is one of around 100 genes that have been selected for the design of antibacterial drugs. The pepA gene encodes leucine aminopeptidase (LAP), an exopeptidase that catalyzes the hydrolysis of leucine residues from the N-terminus of a protein or peptide. This enzyme was expressed in Escherichia coli, purified and crystallized, and preliminary X-ray structural studies have been carried out. The LAP crystal diffracted to 2.6 A resolution and belonged to the cubic space group P2(1)3. The unit-cell volume of the crystal was compatible with the presence of two monomers in the asymmetric unit.

Cloning, expression, crystallization and preliminary X-ray crystallographic analysis of beta-ketoacyl-ACP synthase III (FabH) from Xanthomonas oryzae pv. oryzae.

The bacterial beta-ketoacyl-ACP synthase III (KASIII) encoded by the gene fabH (Xoo4209) from Xanthomonas oryzae pv. oryzae, a plant pathogen, is an important enzyme in the elongation steps of fatty-acid biosynthesis. It is expected to be one of the enzymes responsible for bacterial blight (BB), a serious disease that results in huge production losses of rice. As it represents an important target for the development of new antibacterial drugs against BB, determination of the crystal structure of the KAS III enzyme is essential in order to understand its reaction mechanism. In order to analyze the structure and function of KAS III, the fabH (Xoo4209) gene was cloned and the enzyme was expressed and purified. The KASIII crystal diffracted to 2.05 A resolution and belonged to the orthorhombic space group P2(1)2(1)2, with unit-cell parameters a = 69.8, b = 79.5, c = 62.3 A. The unit-cell volume of the crystal is compatible with the presence of a single monomer in the asymmetric unit, with a corresponding Matthews coefficient V(M) of 2.27 A(3) Da(-1) and a solvent content of 45.8%.

Cloning, expression, crystallization and preliminary X-ray crystallographic analysis of glutamyl-tRNA synthetase (Xoo1504) from Xanthomonas oryzae pv. oryzae.

The gltX gene from Xanthomonas oryzae pv. oryzae (Xoo1504) encodes glutamyl-tRNA synthetase (GluRS), one of the most important enzymes involved in bacterial blight (BB), which causes huge production losses of rice worldwide. GluRS is a class I-type aminoacyl-tRNA synthetase (aaRS) that is primarily responsible for the glutamylation of tRNA(Glu). It plays an essential role in protein synthesis, as well as the regulation of cells, in all organisms. As it represents an important target for the development of new antibacterial drugs against BB, determination of the three-dimensional structure of GluRS is essential in order to understand its catalytic mechanism. In order to analyze its structure and function, the gltX gene was cloned and the GluRS enzyme was expressed, purified and then crystallized. A GluRS crystal belonging to the monoclinic space group C2 diffracted to 2.8 A resolution and had unit-cell parameters a = 186.8, b = 108.4, c = 166.1 A, beta = 96.3 degrees . The unit-cell volume of the crystal allowed the presence of six to eight monomers in the asymmetric unit, with a corresponding Matthews coefficient (V(M)) range of 2.70-2.02 A(3) Da(-1) and a solvent-content range of 54.5-39.3%.