Gerbils of a seizure-sensitive strain have a mitochondrial inner membrane protein with different isoelectric points from those of a seizure-resistant strain

The distribution of proteins in the cerebral cortex of a seizure-sensitive (SS) strain of gerbil and its seizure-resistant (SR) counterpart was profiled using two-dimensional gel electrophoresis. A series of proteins of similar molecular weight (around 83 kDa) showed small but consistent differences in their isoelectric point (pI) with indistinguishable profiles of distribution between the two strains. Amino acid sequences of peptides produced by limited proteolysis of each protein in the spots from the strains were identical or highly homologous to those of mitofilin, a mitochondrial inner membrane protein (IMMT) in humans. Analysis of cDNA sequences revealed the proteins of these spots to be gerbil mitofilin-like proteins (gIMMT), with a few base substitutions between SS and SR strains, in particular within a region near a putative transmembrane domain that is highly conserved in humans and gerbils. The amino acid at the site was acidic, Glu in humans and Asp in the strain SR of gerbil and a neutral, Asn in strain SS. In addition to these base substitutions, production of multiple species of mRNA for gIMMT by alternative splicing was observed.     

Preparation of 2- and 4-(2-alkylcarbamoyl-1-methylvinyl)-7-alkyloxybenzo[b]furans having potent antagonistic activity against human leukotriene B4 BLT1 and/or BLT2 receptors

(E)-2-Acetyl-4-(2-diethylcarbamoyl-1-methylvinyl)-7-(1-phenylethoxy)benzo[b]furan (4b) with a characteristic conformation and (E)-2-(2-morpholinocarbo-1-methylvinyl)-7-ethoxycarbopropoxybenzo[b]furan ((E)-3b) were prepared and evaluated for their leukotriene B4(LTB4) antagonistic activity. Compound 4b showed potent antagonistic activity against human BLT1 and BLT2 receptors. Compound (E)-3b displayed selective BLT2 receptor antagonistic activity. Both compounds were inactive to cysteinyl LT receptors.     

Stepwise controlled immobilization of colloidal crystals formed by polymer-grafted silica particles

Colloidal crystals formed by polymer-grafted silica particles were immobilized by a stepwise procedure consisting of gelation by radical copolymerization followed by solidification by ring-opening radical polymerization. In the first step, the poly(methyl methacrylate) (PMMA)-grafted silica colloidal crystal suspension was incorporated into the gel without altering the crystal structure by copolymerization of cross-linker, 1,2-dimethylacryloyloxyethane (DME) and methyl methacrylate (MMA). In the second step, ring-opening radical polymerization was performed after substituting the solvent with vinylidene-1,3-dioxolane. By this two-step procedure, the silica particle array of colloidal crystals was immobilized and made into durable material.     

Total synthesis of gambierol

The convergent total synthesis of gambierol (1) is described. The octacyclic ether framework of 1 was constructed via the intramolecular allylation of alpha-chloroacetoxy ether followed by ring-closing metathesis. A modified Stille coupling was successfully applied to the synthesis of the triene side chain.     

Catalytic alkynylation of ketones and aldehydes using quaternary ammonium hydroxide base

Catalytic alkynylation of diverse ketones and aldehydes using nonmetallic benzyltrimethylammonium hydroxide or a basic resin of the hydroxide type in DMSO is described. Aliphatic or alicyclic carbonyl partners gave satisfactory results, whereas aromatic ones afforded products with low yields. When aromatic aldehydes were reacted with phenylacetylene, enones such as chalcone derivatives were obtained in place of ynols. These organobase-catalyzed systems provide a practical nonmetallic protocol for C[bond]C formation.     

A Novel Thermooptical Detection Method for Enzyme Reaction Based on the Optical Beam Deflection Induced by Reaction Heat

A novel thermooptical detection method for enzyme reaction based on the optical beam deflection induced by reaction heat is proposed. A probe beam passes through a CCl₄ phase above which a model enzyme reaction occurs. The enzyme reaction medium is arranged to be either interfaced directly with the CCl₄ phase or separated from the CCl₄ phase by a thin gold film. The decomposition reaction of hydrogen peroxide catalyzed by catalase is used as a model enzyme reaction. In the arrangement that the reaction medium is interfaced directly with the CCl₄ phase, both the reaction heat and the reaction product O₂ diffuse into the CCl₄ phase, and thus generate temperature and concentration gradients, respectively. Since both the temperature and concentration gradients induce the deflections of the probe beam, two peaks are observed in the deflection signal. On the other hand, in the arrangement that the reaction medium is separated from the CCl₄ phase by the gold film, only the deflection signal generated by the temperature gradient is detected. The quantitative relations between the deflection signals induced by the reaction heat and the concentrations of catalase and H₂O₂ are investigated. Under the present batch experimental conditions, deflection signals are linear in the concentration ranges of 4 × 10⁻³-4 × 10⁻² mol/liter for H₂O₂, and 11-550 μg/ml (activity, 11-550 unit/ml) for catalase solution, respectively. The detection limits for H₂O₂ and catalase solution are 4 × 10⁻³ mol/liter and 11 μg/ml (activity, 11 unit/ml), respectively. In addition, the possibilities of development as a new thermooptical biosensor and application to the determination of activity distribution of this method are also discussed.     

Hybridization-promoted and cytidine-selective activation for cross-linking with the use of 2-amino-6-vinylpurine derivatives

Recently, we have proposed a new concept for cross-linking agents with inducible reactivity, in which the highly reactive cross-linking agent, the 2-amino-6-vinylpurine nucleoside analogue (1), can be regenerated in situ from its stable precursors, the phenylsulfide (4) and the phenylsulfoxide (3) derivatives, by a hybridization-promoted activation process with selectivity to cytidine. The phenylsulfide precursor (4) exhibited cross-linking ability despite its high stability toward strong nucleophiles such as amines and thiols. In this study, we investigated the substituent effects of the phenylsulfide group on the cross-linking reaction, and determined the 2-carboxy substituent of the phenylsulfide derivative (11k) as an efficient cross-linking agent with inducible reactivity. Detailed investigations have shown that the phenylsulfoxide (3) and phenylsulfide (4) precursors produce the 2-amino-6-vinylpurine nucleoside (1) as the common reactive species. It has been concluded that the nature of the inducible reactivity of the precursors (3 and 4) is acceleration of their elimination to the 2-amino-6-vinylpurine nucleoside (1) through the selective process in the duplex with the ODN having cytidine at the target site.     

Boc–Pro–Hyp–Gly–OBzl and Boc–Ala–Hyp–Gly–OBzl,two repeating triplets found in collagen

The protected tripeptides benzyl N‐{2‐[N‐(tert‐butoxy­carbon­yl)­prol­yl]‐4‐hydroxy­prol­yl}glycinate or Boc–Pro–Hyp–Gly–OBzl, C₂₄H₃₃N₃O₇, and benzyl N‐{2‐[N‐(tert‐butoxy­carbon­yl)­alan­yl]‐4‐hydroxy­prol­yl}glycinate or Boc–Ala–Hyp–Gly–OBzl, C₂₂H₃₁N₃O₇, are the minimum repeating triplets found in collagen. Within the crystal structure of each are two independent peptide mol­ecules with similar structures. The peptides are arranged anti­parallel to one another and inter­act through hydrogen bonds involving the main chains and the 4‐hydroxy­prolyl groups. The structures exhibit characteristics of a triple helix, but the peptides tend to assume a sheet‐like structure.     

On some elliptic curves defined over Q of free rank ≧9

Infinitely many elliptic curves defined over Q of free rank 9 are explicitly constructed.     

Interactions of Na-salts and 1-propanol in 1-propanol-Na-Salt-H2O systems: toward an understanding the Hofmeister series (IV)

The excess chemical potential of 1-propanol (1P), muE1P, was evaluated in ternary 1P-Na-salt(S)-H2O at 25 degrees C. The counter anions of the Na-salts studied are SO42-, F-, Cl-, I-, and ClO4-. The effect of the anion on muE1P follows the Hofmeister ranking, in that the more kosmotropic ions make the muE1P value more positive. We then evaluate the effect of the Na-salt (S) on muE1P, the 1P-S interaction in terms of excess chemical potential, at a semi-infinite dilution. The results indicate that the 1P-S interaction in terms of excess chemical potential is unfavorable (repulsive) for all of the ions studied. The degree of repulsive interaction decreases in the order of the Hofmeister ranking from the kosmotropic to the chaotropic end. Namely, salting-out samples make the excess part of the chemical potential of 1P more unfavorable, while the salting-in counterparts make it less unfavorable. From earlier calorimetric studies on the same ternary systems, the enthalpic 1P-S interaction function, HE 1P-S , was calculated. Hence, the entropy analogue, S1P-S , was also obtained, and a detailed thermodynamic signature of 1P-S interactions became available. This revealed that both HE 1P-S and SE 1P-S decrease from the kosmotropic ion to the middle of the ranking (Cl-), whereupon they turn to increase toward the chaotropic end. Hence, the build up of unfavorable 1P-S interactions in Hofmeister salts (signified by muE1P) relies on a pronounced enthalpy-entropy compensation, which must be accounted for in attempts to understand the molecular mechanisms underpinning Hofmeister effects.