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1.
T Masaki T Tanaka S Tsunasawa F Sakiyama M Soejima 《Bioscience, biotechnology, and biochemistry》1992,56(10):1604-1607
Z-Val-, Z-Pro-, Z-Leu-Leu-, and Z-Leu-Pro-lysinals and BZ-DL-lysinal were chemically synthesized and tested as novel inhibitors for Achromobacter protease I (API), a lysine-specific serine protease. Among the lysinal derivatives tested, Z-Val-lysinal was the most potent competitive inhibitor, its Ki being estimated as 6.5 nM in an esterolytic assay with Tos-Lys-OMe. In an amidolytic assay, Z-Leu-Leu-lysinal was the most potent inhibitor and the apparent mode of inhibition was non-competitive. The Kis of the other lysinal derivatives in both esterolytic and amidolytic assays were more than 10(3) times lower than that of leupeptin. Z-Val-lysinol, lacking the aldehyde group, was a poor competitive inhibitor. These results suggest that acyl-, acylaminoacyl-, and acylpeptidyllysinals function as a transition-state inhibitor for Achromobacter protease I. 相似文献
2.
Sakaba Tomoka Soejima Akiko Fujii Shinji Ikeda Hajime Iwasaki Takaya Saito Hiroaki Suyama Yoshihisa Matsuo Ayumi Kozhevnikov Andrey E. Kozhevnikova Zoya V. Wang Hongfeng Wang Siqi Pak Jae-Hong Fujii Noriyuki 《Journal of plant research》2023,136(4):437-452
Journal of Plant Research - A group of temperate grassland plant species termed the “Mansen elements” occurs in Japan and is widely distributed in the grasslands of continental East... 相似文献
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Mechanism for generation of hydrogen peroxide and change of mitochondrial membrane potential during rotenone-induced apoptosis 总被引:13,自引:0,他引:13
Rotenone, an inhibitor of NADH dehydrogenase complex, is a naturally occurring insecticide, which is capable of inducing apoptosis. Rotenone-induced apoptosis is considered to contribute to its anticancer effect and the etiology of Parkinson's disease (PD). We demonstrated that rotenone induced internucleosomal DNA fragmentation, DNA ladder formation, in human cultured cells, HL-60 (promyelocytic leukemia) and BJAB cells (B-cell lymphoma). Flow cytometry showed that rotenone induced H2O2 generation, followed by significant changes in the mitochondrial membrane potential (DeltaPsim). Caspase-3 activity increased in HL-60 cells in a time-dependent manner. These apoptotic events were delayed in HP100 cells, an H2O2-resistant clone of HL-60, confirming the involvement of H2O2 in apoptosis. Expression of anti-apoptotic protein, Bcl-2, in BJAB cells drastically inhibited DeltaPsim change and DNA ladder formation but not H2O2 generation, confirming the participation of mitochondrial dysfunction in apoptosis. NAD(P)H oxidase inhibitors prevented H2O2 generation and DNA ladder formation. These results suggest that rotenone induces O2(-)-derived H2O2 generation through inhibition of NADH dehydrogenase complex and/or activation of NAD(P)H oxidase, and H2O2 generation causes the disruption of mitochondrial membrane in rotenone-induced apoptosis. 相似文献
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The genusPittosporum includes about 160 species. Four species ofPittosporum occur in the Bonin Islands, and all of these are endemic to the islands. Electrophoretic studies of the four endemic species,P. tobira, from the Japanese mainland, andP. lutchuense var.denudatum from the Ryukyu Islands, were used to determine the origin and speciation pattern of the endemic species.
259 individuals were sampled from ten populations. Twenty loci in nine enzyme systems were resolved and used to calculate
the gene frequencies for each population. A low genetic diversity was observed in three of the Bonin Island species, as is
reported for other oceanic island plants. The exception,P. boninense, has the largest population size and widest distribution. A dendrogram generated by the UPGMA method shows two clusters.
One consists of only the Bonin endemics, suggesting a monophyletic origin for these species. 相似文献
7.
We have developed a computational method of protein design to detect amino acid sequences that are adaptable to given main-chain coordinates of a protein. In this method, the selection of amino acid types employs a Metropolis Monte Carlo method with a scoring function in conjunction with the approximation of free energies computed from 3D structures. To compute the scoring function, a side-chain prediction using another Metropolis Monte Carlo method was performed to select structurally suitable side-chain conformations from a side-chain library. In total, two layers of Monte Carlo procedures were performed, first to select amino acid types (1st layer Monte Carlo) and then to predict side-chain conformations (2nd layers Monte Carlo). We applied this method to sequence design for the entire sequence on the SH3 domain, Protein G, and BPTI. The predicted sequences were similar to those of the wild-type proteins. We compared the results of the predictions with and without the 2nd layer Monte Carlo method. The results revealed that the two-layer Monte Carlo method produced better sequence similarity to the wild-type proteins than the one-layer method. Finally, we applied this method to neuraminidase of influenza virus. The results were consistent with the sequences identified from the isolated viruses. 相似文献
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The inactivation of papain brought about by low concentration of urea or guanidine hydrochloride was found to be a non-competitive type and that of cyanate ion to be a mixed type. The results are presented as Lineweaver-Burk plots.These inactivations are not due to a change in the secondary structure of papain molecule as a result of the measurements of optical rotatory dispersion, circular dichroism, and UV-difference spectra. 相似文献
9.
Yoshichika Takamura Tomiko Takamura Masami Soejima Teijiro Uemura 《Bioscience, biotechnology, and biochemistry》2013,77(5):718-728
Maleate cis-trans isomerase in Alcaligenes faecalis IB–14 was induced by malonate and purified about 100-fold over the crude cell-free extract by treatments of ammonium sulfate fractionation, Sephadex G–100 gel filtration, DEAE-cellulose and DEAE-Sephadex A–50 column chromatography. The preparation was shown to be monodisperse on ultracentrifugal analysis and Svedberg value was found to be 3.84 S.The enzyme was most active at pH value around 8.3 and was stable over the range of pH 5.0 to 7.0 in the presence of dithiothreitol (DTT) for a few weeks, but in the absence of it, the enzyme activity was markedly decreased, especially in the alkaline region. The enzyme activity was inhibited by various sulfhydryl reagents and oxidizing agents, whereas it was not affected by metal chelating agents. The inhibition by Hg2+ and PCMB was overcome by the addition of sulfhydryl compounds such as DTT, 2-mercaptoethanol, l-cysteine and glutathione. It was observed that the enzyme did not require co-factor for its function.Kinetic studies showed that Michaelis constant for maleate was 2.8×10?3 m and the enzyme did not catalyze the reverse reaction. 相似文献
10.
Takao?MunemotoEmail author Akinori?Masuda Nobuatsu?Nagai Muneki?Tanaka Soejima?Yuji 《BioPsychoSocial medicine》2013,7(1):9