Capillary electrophoretic discrimination of single nucleotide polymorphisms using an oligodeoxyribonucleotidepolyacrylamide conjugate as a pseudo-immobilized affinity ligand: optimum ligand length predicted by the melting temperature values.

We developed a weak-affinity separation system for single-nucleotide polymorphisms (SNPs) based on capillary electrophoresis. In this approach, single-stranded DNA (ssDNA)-polyacrylamide (polyAAm) conjugate was used as a pseudo-immobilized affinity ligand to separate the target DNA, cytochrome P450 2C9 (CYP2C9), and its point mutant. The ligand DNA was designed to be complementary to the normal DNA, and the target DNA was electrophoretically separated by the difference in the affinity with the pseudo-immobilized ligand in the capillary. We showed that the separation efficiency was closely associated with the Tm value of double-stranded DNA (dsDNA) consisting of the target and ligand DNA, which depends on the measurement conditions, such as the base number of the ligand DNA and the concentration of Mg2+ in the buffer solution.     

Improvement of wettability and detergency of polymeric materials by excimer UV treatment

The 172 nm ultraviolet (UV) excimer light was exposed to polyethylene (PE), polypropylene, poly(ethylene terephthalate) and nylon 6 surfaces in ambient air. Changes in the contact angle and particle deposition in liquid due to UV treatment were investigated from the viewpoints of wettability and detergency. For all polymers, the wettability and the acid-base component of the surface free energy evaluated by the contact angle measurements increased remarkably by UV treatment of 1 min. From surface analyses of the polymer surfaces by X-ray photoelectron spectroscopy and atomic force microscopy, oxygen concentration was found to increase after UV treatment, whereas little topographical change was observed. The deposition of PE and nylon 12 particles onto the polymer surface was examined, in situ, in water, water/ethanol mixture, ethanol and n-heptane. Although the number of deposited particles was largely dependent on the kinds of the particle, the substrate and the liquid, a significant decrease in the deposition due to UV treatment was confirmed in any system.     

The three-dimensional structure of aspergilloglutamic peptidase from Aspergillus niger

Aspergilloglutamic peptidase from Aspergillus niger is a novel pepstatin-insensitive acid endopeptidase distinct from the well-studied aspartic peptidases, and thus is an interesting target for protein structure/function studies. In the present study, we have determined the three-dimensional structure of the enzyme by X-ray crystallography to a 1.4-Å resolution. The results revealed that the enzyme has a unique structure, composed of two seven-stranded anti-parallel β-sheets which form a β-sandwich structure and appear to have a partial two-fold symmetry, suggesting its possible evolution by gene duplication and that the glutamic acid-110 and glutamine-24 in the heavy chain form a catalytic dyad, consistent with our results obtained by site-directed mutagenesis.     

Development of a new traceless aniline linker for solid-phase synthesis of azomethines. Application to parallel synthesis of a rod-shaped liquid crystalline library

A new traceless linker was developed to synthesize a library of 42 compounds possessing an azomethine linkage using combinatorial solid-phase parallel synthesis. The loading of the substrates on a solid support and cleavage from the solid support were performed by an imine synthesis and by imine-exchanged process under mild conditions, respectively. Thioesters with a hydroxy group on the central core exhibited liquid crystalline properties with the widest transition temperatures in the library.     

Phase grating generation and optical phase conjugation in photorefractive polymer/dissolved liquid crystal composites

The orientational photorefractive properties of photorefractive mesogenic composites have been investigated by means of two-beam coupling and degenerate four-wave mixing. Photorefractive mesogenic composites, consisting of low molar mass liquid crystals, polymer, and photoconductive sensitizer, constitute novel organic materials possessing high performance photoreractivity. The refractive index change was estimated on the basis of the theory of two-beam coupling and four-wave mixing, and large index modulation of over 0.01 was obtained.     

Microchip electrophoresis for specific gene detection of the pathogenic bacteria V. cholerae by circle-to-circle amplification.

We have developed a new method for a fast and precise analysis of circle-to-circle amplification (C2CA) product for specific gene detection by microchip electrophoresis. In this method, we have added a new enzymatic step to the C2CA reaction, which could be carried out isothermally at 37 degrees C. Compared to the original single-stranded DNA, the double-stranded DNA that is produced by this enzymatic reaction is more reliable for analysis by microchip electrophoresis. C2CA product was detected within 55 s with high reproducibility by this method which was successfully applied to the detection of 10-ng genomic DNA of the pathogenic bacteria Vibrio. cholerae within 110 s. Purification was found to be an indispensable step for the analysis of the C2CA product of genomic DNA samples.     

Facile assay of telomerase activity utilizing a DNA-detectable chemiluminogenic reagent.

Telomerase shows increased activity in most human cancers and germ line cells, but not in normal human somatic cells. We describe a novel chemiluminescence method for the facile assay of telomerase activity in human cells. The telomerase substrate was incubated with the cell lysate containing various amounts of telomerase, and then the telomerase product was amplified by the polymerase-chained reaction (PCR). The PCR products were separated from the excess substrate, primer and deoxyribonucleotide triphosphates by a centrifugal filter, which distinguished different molecular sizes. The isolated products were reacted with a DNA-detectable chemiluminogenic reagent, 3,4,5-trimethoxyphenylglyoxal. The proposed assay method gave linearity for the telomerase activity in 100 to 10000 cells (r2=0.997), and allowed the assay not only of lower activity, but also of higher activity of telomerase without the requirement of any special labeled-PCR primers in the assay system.     

Hydrohalogenation of 1- and 2-vinylindazoles

The electronic absorption spectra of 1-vinyl- and 2-vinylindazoles and their protonated forms were analyzed. The spectra were subjected to quantum-chemical calculation within the Pariser-Parr-Pople (PPP) -electron approximation, and the thermodynamic parameters of the reaction of indazoles with phenol (K_as and H) were calculated. It is shown that 1-vinylindazole adds hydrogen halides to the nitrogen atom or the double bond of the vinyl group, depending on the reaction temperature. The formation of hydrohalides is characteristic for 2-vinylindazole.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 952–956, July, 1982.     

Synthesis of 1,4-dihydro-2-methyl-4-oxo-3-quinolineglyoxylic acid and related compounds

The synthesis of 1,4-dihydro-1-methoxy or ethyl -2-methyl-4-oxo-3-quinolineglyoxylic acid derivatives are described. α-Acetoxy-1,4-dihydro-1-hydroxy-2-methyl-4-oxo-3-quinolineacetic acid esters ( 7a, 7a ), which are key intermediates, were prepared by catalytic hydrogenation of 2-acetoxy-3-acetyl-4-hydroxy-4-(2-nitrophenyl) crotonic acid lactone ( 6 ) in methanol or ethanol.