Crystal structure of annexin V with its ligand K-201 as a calcium channel activity inhibitor.

The crystal structure of recombinant human annexin V complexed with K-201, an inhibitor of the calcium ion channel activity of annexin V, was solved at 3.0 A by molecular replacement including the apo and high-calcium forms. K-201 was bound at the hinge region cavity formed by the N-terminal strand and domains II, III and IV, at the side opposite the calcium and membrane-binding surface, in an L-shaped conformation. Based on the complex and other annexin structures, K-201 is proposed to restrain the hinge movement of annexin V in an allosteric manner, resulting in the inhibition of calcium movement across the annexin V molecule.

Direct measurement of nitric oxide during experimental cardiopulmonary bypass.

We developed a system to measure nitric oxide (NO) concentration during cardiopulmonary bypass in anaesthetized pigs (n = 6). A T-shaped connector, attached to an NO sensor, was mounted in the extracorporeal circuit at two measuring sites: proximal to the membrane oxygenator (venous side) and distal to the arterial line filter (arterial side). After performing a preliminary validation study, we measured plasma NO concentration before and during total cardiopulmonary bypass circulation (non-pulsatile flow 1.5 l/min) and without pulmonary ventilation. After establishing bypass, PaO2 was 318 - 393 mmHg; when PaO2 was decreased to 80 - 100 mmHg, plasma NO concentration in the arterial circuit fell by 39.2 +/- 15.6 nM. There was no observable change in plasma NO concentration at the venous circuit. This new system could be useful in monitoring NO concentration during cardiac surgery with cardiopulmonary bypass, and for understanding the possible pathophysiological roles of hyper-nitric oxaemia in cardiopulmonary bypass-related cardiovascular complications.

Bilberry extract supplementation for preventing eye fatigue in video display terminal workers.

OBJECTIVES: To examine the effect of a dietary supplement containing bilberry extract (BE) on eye fatigue induced by acute video display terminal (VDT) loads. DESIGN AND SETTING: A prospective, randomized, double-blind, placebo-controlled study was performed from August 2012 to February 2013 in the Medical Corporation Jico-kai Yagi Hospital, and the Shinyokohama Shinoharaguchi Orthopedic Surgery and Dermatology Clinic, in Japan. PARTICIPANTS: Two hundred eighty-one office workers aged 20-40 years that used VDTs were screened by critical flicker fusion (CFF) and near point accommodation (NPA). INTERVENTION: The participants were randomized to either a BE (480 mg/day) or placebo (vehicle) group, and took allocated capsule, daily, for 8 weeks. MEASUREMENTS: The CFF, NPA, contrast visual acuity, functional visual acuity, keratoconjunctival epithelial damage, and fluorescein tear film break-up time were examined, and 18 subjective symptoms of eye fatigue were evaluated by questionnaire. Adverse events were reported via medical interviews. Data were collected both before and after VDT load at baseline, and 4, and 8 weeks after daily supplementation with either BE or placebo. RESULTS: Of 281 participants screened, 88 having relatively lower levels of CFF and NPA were enrolled in the study. Of these, 37 control and 43 BE group subjects completed the study. The VDT load-induced reduction in CFF was alleviated after 8 weeks of BE supplementation (95% confidence interval, 0.10-1.60; p=0.023), in contrast to placebo supplementation, while NPA variation was not. Of the subjective symptoms of eye fatigue, VDT load-induced ocular fatigue sensation, ocular pain, eye heaviness, uncomfortable sensation, and foreign body sensation were mitigated more in the BE group than in the control group, at week 8 (p<0.05). There were no severe adverse events in either group. CONCLUSIONS: BE supplementation improved some of the objective and subjective parameters of eye fatigue induced by VDT loads.

Mutagenic effectiveness of 14.1 MeV neutrons and 200 kV X-rays at the dumpy complex locus of Drosophila melanogaster.

The effectiveness of 14.1 MeV neutrons relative to 200 kV X-rays for the induction of the various kinds of dumpy mutation in mature sperm of Drosophila melanogaster was investigated. The estimated RBE values are: 0.52 for all complete mutations; 0.64 for the (olv, ov) types; 0.33 for the (ol, lv, o, v, c) types; 0.33 for all fractional mutations. These data lend support to the thesis that (1) complete dumpy mutations of the olv and ov types are more frequently associated with chromosomal aberrations than those of the ol, lv, o, v and c types, and (2) fractional mutations and complete mutations of the (ol, lv, o, v, c) types are most probably point mutational events.

Comparative induction of somatic eye-color mutations and sex-linked recessive lethals in Drosophila melanogaster by tryptophan pyrolysates.

The mutagenicities of the products of pyrolysis of tryptophan, Trp-P-1 and Trp-P-2, on Drosophila melanogaster were examined by measuring the effects of these compounds in inducing recessive lethals and somatic eye-color mutations. Since negative results have already been obtained by the standard procedure in males, Trp-P-1 and Trp-P-2 (0.75 to 6 mg/ml) in sucrose solution were given to females for assay of recessive lethal mutations in X-chromosomes. These compounds caused a marginal increase above the control level in the mutation frequency. For the assay of effects on somatic eye-color mutations, Trp-P-1 (200 and 400 ppm) and Trp-P-2 (400 and 800 ppm) were fed to male larvae of a tester strain carrying a genetically unstable marker set of z and w+ on the X-chromosome. These compounds caused dose-dependent increases above the control level in somatic eye-color mutations in adults. It is concluded that, under the conditions used, the somatic eye-color mutation system was more sensitive than the recessive lethal system to the mutagenic effects of tryptophan pyrolysates.

The crystal and molecular structure of the trisaccharide erlose trihydrate.

Erlose [beta-D-fructofuranosyl O-alpha-D-glucopyranosyl-(1-->4)-D-glucopyranoside] trihydrate, C18H32 O16.3H2O, M(r) = 558.48, is orthorhombic, P2(1)2(1)2(1) with a = 31.164(7), b = 13.111(5), c = 11.636(5) A, and Z = 8. The structure was solved by direct methods, and refined to R = 0.035 for 3926 observed reflections. The unit cell contains two independent molecules having a similar conformation. The conformation of the alpha-(1-->2) glycosidic linkage is similar to that observed in erlose monohydrate, whereas the conformation of the alpha-(1-->4) glycosidic linkage differs significantly. The molecule has no intramolecular hydrogen-bonds except for the minor components of three-center bonds, but indirect intramolecular hydrogen-bonds through the water molecules are formed. The hydrogen-bond system in the crystal structure consists of infinite and finite chains crosslinked by water molecules.

The crystal and molecular structure of the trisaccharide erlose as the monohydrate.

Erlose [O-beta-D-fructofuranosyl-(1-->2)-O-alpha-D-glucopyranosyl-(1-->4)- alpha-D-glucopyranoside] monohydrate, C18H32O16.H2O, M(r) = 522.45, is orthorhombic, P2(1)2(1)2(1) with a = 30.748 (3), b = 8.757 (1), c = 8.270 (1) A, and Z = 4. The structure was solved by direct methods, and refined to R = 0.048 for 1909 observed reflections. The torsion angles about the (1-->2) and (1-->4) glycosidic bonds are similar to those observed in other sucrose- and maltose-like oligosaccharides. The maltose moiety has an O-3'-H...O-2 intramolecular hydrogen-bond, but the sucrose moiety has no intramolecular hydrogen bonds. The hydrogen bonding in the crystal includes infinite and finite chains crosslinked by the water molecule.

The crystal and molecular structure of beta-D-fructofuranosyl alpha-D-xylopyranoside hemihydrate.

The crystal and molecular structure of beta-D-fructofuranosyl alpha-D-xylopyranoside (xylosucrose) hemihydrate, C11H20O10.0.5H2O, is orthorhombic, P2(1)2(1)2, with a = 20.919(5), b = 18.727(2), c = 7.071(1) A, V = 2770.1(2) A3, Z = 8, and Dx = 1.541 g.cm-3. The structure was solved by direct methods and refined to R = 0.040 for 2564 observed reflections. Two independent xylosucrose molecules exist in the unit cell, and their conformations about the 1-->2' glycosidic bond are similar to sucrose. The orientations of the primary hydroxyl groups in the two molecules differ. An O-1'...O-2 intramolecular hydrogen bond was observed in the one molecule, while an O-6'...O-5 intramolecular hydrogen bond was observed in the other involving disorder of O-6'.

X-ray structure of a pokeweed antiviral protein, coded by a new genomic clone, at 0.23 nm resolution. A model structure provides a suitable electrostatic field for substrate binding.

We have determined the crystal structure of alpha-pokeweed antiviral protein, a member of ribosome-inactivating proteins, at 0.23 nm resolution, by the molecular-replacement method. The crystals belong to the space group P2(1)2(1)2 with unit-cell dimensions a = 4.71, b = 11.63 and c = 4.96 nm, and contain one protein molecule/asymmetric unit based on a crystal volume/unit protein molecular mass of 2.1 x 10(-3) nm3/Da. The crystallographic residual value was reduced to 17.2% (0.6-0.23 nm resolution) with root-mean-square deviations in bond lengths of 1.9 pm and bond angles of 2.2 degrees. The C alpha-C alpha distance map shows that alpha-pokeweed antiviral protein is composed of three modules, the N-terminal (Ala1-Leu76), the central (Tyr77-Lys185) and the C-terminal (Tyr186-Thr266) modules. The substrate-binding site is formed as a cleft between the central and C-terminal modules and all the active residues exist on the central module. The electrostatic potential around the substrate-binding site shows that the central and C-terminal module sides of this cleft have a negatively and a positively charged region, respectively. This charge distribution in the protein seems to provide a suitable interaction with the substrate rRNA.

Novel renin inhibitors containing (2S,3S,5S)-2-amino-1-cyclohexyl-6-methyl-3,5-heptanediol fragment as a transition-state mimic at the P1-P1' cleavage site.

A series of renin inhibitors containing the (2S,3S,5S)-2-amino-1-cyclohexyl-6-methyl-3,5-heptanediol (2-amino-3,5-anti-diol) fragment as a novel transition-state mimic was synthesized, and their biological activities were evaluated. All of the synthesized compounds containing the 2-amino-3,5-anti-diol fragment at the P1-P1' position showed high in vitro renin-inhibitory activity with IC50 values in the 10(-8)-10(-10) M range, and most of them caused a reduction of blood pressure when administered orally to salt-depleted, conscious marmosets. The inhibitor (29) with the 4-hydroxypiperidine residue at the P4 position showed the highest activity in terms of both potency and duration of the blood pressure-lowering effect.

Cloning and crystal structure of hematopoietic prostaglandin D synthase.

Hematopoietic prostaglandin (PG) D synthase is the key enzyme for production of the D and J series of prostanoids in the immune system and mast cells. We isolated a cDNA for the rat enzyme, crystallized the recombinant enzyme, and determined the three-dimensional structure of the enzyme complexed with glutathione at 2.3 A resolution. The enzyme is the first member of the sigma class glutathione S-transferase (GST) from vertebrates and possesses a prominent cleft as the active site, which is never seen among other members of the GST family. The unique 3-D architecture of the cleft leads to the putative substrate binding mode and its catalytic mechanism, responsible for the specific isomerization from PGH2 to PGD2.