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The reduction behaviour from surface to bulk of lanthanum strontium iron perovskite oxide (La 1− x Sr x FeO 3 :0 ⩽ x ⩽ 1.0) particles by CO gas was studied by means of TG, DSC, IR, XRD and X-ray micro-analysis. Interactions with CO and oxygen species that proceed exothermally gave a large weight loss and weight increase respectively. Both increased with the increase of x in La 1− x Sr x FeO 3 . A weight loss was observed in the temperature range 525–725 K as a result of the desorption and reduction by CO of surface oxygen species. A weight increase was observed in the temperature range 775–1125 K as a result of the formation of carbon and/or carbonaceous species. It was concluded that the disproportionation of CO occurs at higher x and higher temperature.

Transparent PZT thin films with perovskite structure were successfully obtained by thermal decomposition of organometallic compounds at the temperatures of 500 to 700° C. The films deposited on platinum substrates were smooth and uniform, but microcrackings were observed in the films deposited on fused silica substrates. The ratio of metal composition in the PZT film agreed with that in the mixture of starting materials. Films obtained at 700° C on platinum substrate showed a hysteresis loop. A spontaneous polarization was 35.65μC cm−2, a saturation remanent polarization was 30.56μC cm−2 and a coercive field was 45 kV cm−1. Dielectric constant and dielectric loss angle were about 300 and 0.05, respectively.

Thermoactinomyces vulgaris α-amylase was purified to an electrophoretically homogeneous state, and its properties and action on starch, pullulan, maltooligosaccharides and partial hydrolyzates of pullulan were studied. Both starch-hydrolyzing and pullulan-hydrolyzing activities of the enzyme were inhibited by Al3+, Cu2+, Hg2+, p-chloromercuribenzoate, maltotriitol, panitol, isopanitol and some microbial α-amylase inhibitors to nearly the same extent. Km and Vmax values of the enzyme for short chain amylose (DP = 17) and pullulan, Ki values for sugar alcohols and α-amylase inhibitors, and the kinetics of the simultaneous presence of short chain amylose and pullulan supported the view that the hydrolytic action of the enzyme on starch and pullulan is due to a single catalytic site. Action patterns of the enzyme on maltooligosaccharides and partially hydrolyzed pullulan were examined, and it was suggested that this α-amylase can attack some of the (1 → 6)-α-d-glucosidic linkages in partial hydrolyzates of pu...

Argininosuccinate lyase (EC 4.3.2.1) is an enzyme present in the brain of ureotelic animals. Using as a probe rat liver argininosuccinate lyase cDNA, already isolated and sequenced (Amaya, Y., Matsubasa, T., Takiguchi, M., Kobayashi, K., Saheki, T., Kawamoto, S. and Mori, M., J. Biochem., 103 (1988) 177-181), we screened a rat brain cDNA library constructed in the lambda gt11 expression vector and obtained a single cDNA clone. This cDNA clone contained an open reading frame encoding a polypeptide of 461 amino acid residues (predicted Mr = 51,390), a 5'-untranslated sequence of 967 bp and a 3'-untranslated sequence of 74 bp. The length of the 5'-non-coding region of the cDNA seems to be one of the longest among the cDNAs heretofore isolated. A comparison of the brain cDNA sequence (2424 bp) with the corresponding region of the liver cDNA (1574 bp) revealed differences in 5 nucleotides. The brain clone contained A----G and C----G base differences from the hepatic sequence, resulting in amino acid changes from Tyr and Arg in the liver clone, to Cys and Gly in the brain clone, respectively. The other 3 nucleotide differences are silent with respect to the amino acid sequence of the protein. Therefore, the amino acid sequence of the brain argininosuccinate lyase, as deduced from the nucleotide sequence of its cDNA clone, was identical with that of the liver protein, except for two amino acid residues. These minor changes may reflect a microheterogeneity of the argininosuccinate lyase gene. The brain and liver enzymes seem to be encoded by the same structural gene.

The action of Thermoactinomyces vulgaris α-amylase was examined in order to elucidate whether this α-amylase catalyzes the hydrolysis of α-1, 4- and α-l, 6-glucosidic linkages in some oligosaccharides at the same catalytic site. The optimum pH for its action on maltotriose and isopanose (α-d-Glcp-(l→4)-α-d-Glcp-(1→6)-d-Glcp) was 4.5, which was the same as the value for starch and pullulan. Hydrolysis patterns of isopanose by this α-amylase were dependent on the substrate concentration. At a low substrate concentration (0.5%) equimolar maltose and glucose were produced from isopanose. At a high substrate concentration (4.0%) a small amount of isomaltose was found besides maltose and glucose, while the molar ratio of glucose to maltose plus isomaltose was unity at the early reaction stages. Hydrolysis patterns of reducing end-(14C)-labeled maltotriose was also dependent on substrate concentration. Increasing the substrate concentration from 0.5 to 4.0%, the molar ratio of labeled glucose to labeled maltose ...

Polycrystalline zinc oxide film was prepared as follows. Zinc naphthenate was coated on a glass or fused silica substrate. The coated zinc naphthenate was decomposed thermally by calcining at 300°C in vacuum or air to form amorphous zinc oxide. On calcining zinc naphthenate at 400°C for 1h, the decomposition was completed and a transparent and uniform film was obtained. However, the amorphous zinc oxide produced by hydrolysis of zinc naphthenate in the presence of small amounts of water (17.5mmHg) crystallized rapidly at 200°C. Consequently, no uniform film was observed, and fine powder of zinc oxide deposited on the substrate. Thus, the uniformity of the film is closely related to the crystallization temperature of amorphous zinc oxide.The thickness attained to 2μ on repeating the coating and calcining procedures. Preferred orientation with c-axis perpendicular to the film surface developed with an increase in the thickness.The electrical resistivity of the film having the thickness of 1μ was 109Ω-cm at room temperature. The temperature dependence resistivity had a minimum at 280-290°C and a maximum at 420-430°C.

The alkaline proteinase gene from Pseudomonas aeruginosa IFO 3455 was cloned and expressed in Escherichia coli.

An 8.3 Kb DNA fragment was cloned from Pseudomonas aeruginosa IFC 3455. This fragment-containing Escherichia clone, pEL2, produced a high level of elastase activity. A smaller EcoRI-KpnI fragment was subcloned into pUC118 and E. coli HB101 was transformed with the plasmid. A deletion mutant clone was also constructed in the same bacteria. These deletion mutants were tested for elastase activity and it became clear that the full length of the elastase gene was 1.0–1.3 Kb. DNA sequencing analysis revealed that this DNA fragment contains the DNA sequence coding N-terminal amino acid sequence of the elastase protein.

The DNA encoding the elastase of Pseudomonas aeruginosa IFO 3455 was cloned, and its complete nucleotide sequence was determined. When the cloned gene was ligated to pUC18, the Escherichia coli expression vector, bacteria carrying the gene exhibited high levels of both elastase activity and elastase antigens. The amino acid sequence, deduced from the nucleotide sequence, revealed that the mature elastase consisted of 301 amino acids with a relative molecular mass of 32,926 daltons. The amino acid composition predicted from the DNA sequence was quite similar to the chemically determined composition of purified elastase reported previously. We also observed nucleotide sequence encoding a signal peptide and "pro" sequence consisting of 197 amino acids upstream from the mature elastase protein gene. The amino acid sequence analysis revealed that both the N-terminal sequence of the purified elastase and the N-terminal side sequences of the C-terminal tryptic peptide as well as the internal lysyl peptide fragment were completely identical to the deduced amino acid sequences. The pattern of identity of amino acid sequences was quite evident in the regions that include structurally and functionally important residues of Bacillus subtilis thermolysin.

The bovine papilloma virus (BPV) recombinant which carried class II MHC (A s d ) gene (pBPAs-d) has been constructed at first. The recombinant plasmid was introduced into the mouse B cell hybridoma by co-transfection method with neomycin resistance gene. Uing this method we could impose into B cell hybridomas many copies of A s d genes extrachromosomally. The several transfectants which had been introduced only beta chain gene of I-Ad have been revealed to expressed the I-Ad proteins on the cell surface by direct immunofluorescent technique. Moreover these I-Ad molecules could induce the IL-2 production of the I-Ad restricted autoreactive T cell hybridoma. So I-Ad molecules which express on the cell surface of the transfectants are fully functional to the T-cell response. RNA dot-blot analysis has revealed that the cells express not only A s d gene but also Ad gene. Thus, A s d gene transfection induced the expression of internally latent Ad gene by trans gene effect.

DNA vaccination has been shown to induce immunity against several different pathogens including HIV-1. The authors demonstrate here that administration of DNA vaccines via the intranasal route is sufficient to induce immune responses both at distal mucosal sites and systemically. Since transmission of HIV-1 occurs largely across mucosal surfaces, the intranasal route provides a further means of application for DNA immunization.