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61.
62.
In vitro cytotoxicity of non-cyt inclusion proteins of a Bacillus thuringiensis isolate against human cells, including cancer cells 总被引:1,自引:0,他引:1
Kim HS Yamashita S Akao T Saitoh H Higuchi K Park YS Mizuki E Ohba M 《Journal of applied microbiology》2000,89(1):16-23
A soil isolate designated 90-F-45-14, belonging to Bacillus thuringiensis serovar dakota (H15), was examined for characterization of in vitro cytotoxicity, associated with parasporal inclusion proteins, against human cells. When activated with proteolytic processing, inclusion proteins of the isolate 90-F-45-14 exhibited a moderate cytotoxicity against the human uterus cervix cancer cells (HeLa) with an EC(50) value of 60.8 microg ml(-1), while showing extremely high activities on the human leukaemic T cells (MOLT-4) and the normal T cells with EC(50) values of 0.27 and 0.20 microg ml(-1), respectively. Anti-leukaemic cell activity of the 90-F-45-14 proteins was eight to nine times greater than that of the B. thuringiensis serovar israelensis proteins containing the Cyt1 protein, a broad-spectrum cytolysin. The cytopathy by the 90-F-45-14 proteins was characterized by marked cell-ballooning, while the israelensis proteins induced early breakdown of the cells due to cytolysis. Inclusions of the isolate consisted of five major polypeptides of 170, 103, 73, 40 and 32 kDa. A 100% homology was observed in the sequence of 15 N-terminal amino acids between the proteins of 170 and 103 kDa. There was no N-terminal sequence homology between 90-F-45-14 proteins and the existing Cry/Cyt proteins of B. thuringiensis. Proteolytic processing by proteinase K yielded several proteins with molecular masses ranging from 40 to 28 kDa. 相似文献
63.
In the brain, many functional modules interact with each other to execute complex information processing. Understanding the nature of these interactions is necessary for understanding how the brain functions. In this study, to mimic interacting modules in the brain, we constructed a hybrid system mutually coupling a hippocampal CA3 network as an actual brain module and a radial isochron clock (RIC) simulated by a personal computer as an artificial module. Return map analysis of the CA3-RIC system's dynamics showed the mutual entrainment and complex dynamics dependent on the coupling modes. The phase response curve of CA3 was modeled regarding the CA3 as a nonlinear oscillator. Using the phase response curves of CA3 and RIC, we reconstructed return maps of the hybrid system's dynamics. Although the reconstructed return maps almost agreed with the experimental data, there were deviations dependent on the coupling mode. In particular, we noted that the deviation was smaller under the bidirectional coupling conditions than during the one-way coupling from RIC to CA3. These results suggest that brain modules may flexibly change their dynamical properties through interaction with other modules. 相似文献
64.
Adenine excisional repair function of MYH protein on the adenine:8-hydroxyguanine base pair in double-stranded DNA 总被引:5,自引:2,他引:3
Shinmura K Yamaguchi S Saitoh T Takeuchi-Sasaki M Kim SR Nohmi T Yokota J 《Nucleic acids research》2000,28(24):4912-4918
Adenine paired with 8-hydroxyguanine (oh8G), a major component of oxidative DNA damage, is excised by MYH base excision repair protein in human cells. Since repair activity of MYH protein on an A:G mismatch has also been reported, we compared the repair activity of His6-tagged MYH proteins, expressed in Spodoptera frugiperda Sf21 cells, on A:oh8G and A:G mismatches by DNA cleavage assay and gel mobility shift assay. We also compared the repair ability of type 1 mitochondrial protein with type 2 nuclear protein, as well as of polymorphic type 1-Q324 and 2-Q310 proteins with type 1-H324 and 2-H310 proteins by DNA cleavage assay and complementation assay of an Escherichia coli mutM mutY strain. In a reaction buffer with a low salt (0–50 mM) concentration, adenine DNA glycosylase activity of type 2 protein was detected on both A:oh8G and A:G substrates. However, in a reaction buffer with a 150 mM salt concentration, similar to physiological conditions, the glycosylase activity on A:G, but not on A:oh8G, was extremely reduced and the binding activity of type 2 protein for A:G, but not for A:oh8G, was proportionally reduced. The glycosylase activity on A:oh8G and the ability to suppress spontaneous mutagenesis were greater for type 2 than type 1 enzyme. There was apparently no difference in the repair activities between the two types of polymorphic MYH proteins. These results indicate that human MYH protein specifically catalyzes the glycosylase reaction on A:oh8G under physiological salt concentrations. 相似文献
65.
Sugano K Yoshida S Takaku M Haramura M Saitoh R Nabuchi Y Ushio H 《Bioorganic & medicinal chemistry letters》2000,10(17):1939-1942
The intestinal permeability of benzamidine analogue thrombin inhibitor is correlated with molecular volume, lipophilicity (calculated log P and IAM column capacity factor), hydrogen bond acidity/basicity and dipolarity. 相似文献
66.
A New System for Stringent, High-Titer Vesicular Stomatitis Virus G Protein-Pseudotyped Retrovirus Vector Induction by Introduction of Cre Recombinase into Stable Prepackaging Cell Lines 总被引:3,自引:2,他引:1
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67.
Miura I; Ohtani H; Nakamura M; Ichikawa Y; Saitoh K 《Molecular biology and evolution》1998,15(12):1612-1619
Sex chromosomes of the Japanese frog Rana rugosa are heteromorphic in the
male (XX/XY) or in the female (ZZ/ZW) in two geographic forms, whereas they
are still homomorphic in both sexes in two other forms (Hiroshima and
Isehara types). To make clear the origin and differentiation mechanisms of
the heteromorphic sex chromosomes, we isolated a sex-linked gene, ADP/ATP
translocase, and constructed a phylogenetic tree of the genes derived from
the sex chromosomes. The tree shows that the Hiroshima gene diverges first,
and the rest form two clusters: one includes the Y and Z genes and the
other includes the X, W, and Isehara genes. The Hiroshima gene shares more
sequence similarity with the Y and Z genes than with the X, W, and Isehara
genes. This suggests that the Y and Z sex chromosomes originate from the
Hiroshima type, whereas the X and W chromosomes originate from the
Isehara-type sex chromosome. Thus, we infer that hybridization between two
ancestral forms, with the Hiroshima-type sex chromosome in one and the
Isehara-type sex chromosome in the other, was the primary event causing
differentiation of the heteromorphic sex chromosomes.
相似文献
68.
The usefulness of RT-PCR for the detection of MHV in tissues and feces of experimentally infected animals has been reported, but it was unclear whether the method was also applicable for the detection of MHV during a natural outbreak. Enterotropic infection is considered to be the most common form of natural infection among various forms of MHV infection. In this paper, RT-nested PCR was performed to detect MHV excreted in the feces during an outbreak in an immunocompromised A/WySnJ mouse colony. The expected bands were amplified after nested PCR from 20 fecal samples out of 37. These results showed that RT-nested PCR could be applicable for the diagnosis for MHV natural infection. 相似文献
69.
The parasporal inclusion proteins of the type strain of Bacillus thuringiensis serovar higo (H44), that have moderate mosquitocidal activity, were characterized. The purified parasporal inclusions, spherical in shape, were examined for activity against the two mosquito species, Culex pipiens molestus and Anopheles stephensi and the moth-fly, Telmatoscopus albipunctatus . The LC50 values of the inclusion for the two mosquitoes were 3·41 and 0·15 μg ml−1 , respectively. No mortality was shown for T. albipunctatus larvae by the inclusions at concentrations up to 1 mg ml−1 . Solubilized parasporal inclusions exhibited no haemolytic activity against sheep erythrocytes. Parasporal inclusions consisted of eight proteins with molecular masses of 98, 91, 71, 63, 59, 50, 44 and 27 kDa. Of these, the 50 and 44 kDa proteins were the major components. Analysis with immunoblotting revealed that, among several inclusion proteins of B. thuringiensis serovar israelensis, only two proteins of 130 kDa and 110 kDa reacted weakly with antibodies against higo proteins. N-terminal amino acid sequences of the 98, 91, and 71 kDa proteins showed 85–100% identity to those of the two established Cry protein classes, Cry4A and Cry10A. 相似文献
70.
Yasuyuki Ishibashi Takashi Saitoh Syuiti Abe Michihiro C. Yoshida 《Population Ecology》1998,40(1):51-59
Kinship amongClethrionomys rufocanus was investigated during the winter of 1992/93 in a 3-ha enclosure using both molecular and catch-mark-release techniques.
Forty-six adult voles (22 males and 24 females) having high heterozygosities, which were collected from several natural populations,
were released into the enclosure on 29 September 1992. Most fall-born individuals of both sexes stayed in their natal site
during the non-breeding period (December–March), although reproductively active females dispersed during the fall breeding
season (October–November). These philopatric individuals aggregated and formed an maternal family in the winter. Several females
which failed to reproduce were solitary during this season. Some individuals which were derived from several families also
aggregated into a mixed lineage group. Survival rate of fall-born voles from earlier litters was higher than that from later
ones. Maternal families broke up soon after the onset of spring reproduction. Most females established a territory near the
wintering site and made a kincluster, in which close relatives neighbored each other. Maternal families in winter bring about
female kin-clusters in spring, which may influence reproductive output in the breeding season. 相似文献