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21.
The ionic strength dependence of the reaction rate between protein and dichloride anion radical has been investigated by flash photolysis of aqueous chloride-containing lysozyme, ribonuclease A, or insulin. The rate constant for the reaction of lysozyme or ribonuclease A with dichloride anion radicals decreases with increasing ionic strength, while it increases for insulin. The dependence was found to obey an equation derived from the theory of Debye and Hückel or the equation of Wherland and Gray for lysozyme within experimental errors. For ribonuclease A, however, it deviates largely from these equations. In the case of insulin a moderate deviation was observed. The different behavior in the ionic strength dependence is discussed in terms of the electric charge distribution in the protein molecules. 相似文献
22.
Yuzuru Mikami Sen Feng Yu Katsukiyo Yazawa Kazutaka Fukushima Akio Maeda Jun Uno Kiyoshi Terao Naoki Saito Akinori Kubo Ken -ichiro Suzuki 《Mycopathologia》1990,112(2):113-118
During our studies on toxic substances from clinically isolated Nocarida, a new isolate identified as Nocardia otitidiscaviarum from cutaneous nocardiosis was found to produce a toxic substance called HS-6 that had strong in vitro as well as in vivo toxicity. The mouse intraperitoneal LD50 value was 1.25 mg/kg and the ED50 value for L1210 cultured cells was 0.3 ng/ml. The structure of HS-6 was determined and found to belong to the 16-membered macrocyclic group with a molecular formula of C43H68O12. HS-6 also showed activity against pathogenic fungi such as Cryptococcus neoformans. 相似文献
23.
Tatsuo Nakahara Makoto Hirano Takashi Matsumoto Toshihide Kuroki Yoshinori Tatebayashi Tetsuyuki Tsutsumi Kouji Nishiyama Hiroaki Ooboshi Kaoru Nakamura Hiroshi Yao Akio Shiraishi Michinori Waki Hideyuki Uchimura 《Neurochemical research》1990,15(6):609-611
DNA and RNA contents in 20 brain regions or nuclei of the rat were determined by a highly sensitive method using high-performance liquid chromatography with electrochemical detection. The high DNA and RNA contents were found in the hypothalamic nuclei, especially the median eminence-arcuate nucleus. These results may be available for the preparation of nucleic acids as the regional control. 相似文献
24.
Protoplasts isolated enzymatically from juvenile leaflets of sporophytes in fern Lyqodium japonicum were inoculated in a MS medium containing NAA 2.7 m, BAP 2.2 m, 0.6 M mannitol, and 0.05 M sucrose. Cell division took place within 8 days of culture initiation, and after 30 days cell-clusters with 10–15 cells were observed. When the cell-clusters were transferred into fresh hormone-free medium containing no mannitol, they developed rhizoids and protonema-like regenerants. About 2 months later, cordate prothallia developed bearing both antheridia and archegonia.Abbreviations MS
Murashige and Skoog (1962)
- NAA
naphthalene acetic acid
- BAP
6-benzylaminopurine 相似文献
25.
Juan M. R. Aparicio Akemi Wakisaka Akio Takada Nobuo Matsuura Miki Aizawa 《Immunogenetics》1988,28(4):240-246
Fifty-six unrelated Japanese patients with insulin-dependent diabetes mellitus (IDDM) were HLA-typed, and restriction fragment length polymorphism (RFLP) analysis was performed after enzyme digestion with Bam HI and Taq I by using both DR and DQ probes. As previously reported, increased frequencies of Bw54, Cw1, DR4, and DRw53, which are in strong linkage disequilibrium in the Japanese population and make the characteristic Japanese haplotype, were confirmed. DQw4, a new allele of the DQ system recognized by the monoclonal antibody HU-46 and in linkage disequilibrium with this haplotype, presented the highest IDDM association. The RFLP analysis also showed the strongest correlation to IDDM when the DQ probe was applied. These results indicate that HLA-DQ might play the most important role in the development of IDDM in Japanese as well as in Caucasians. The correlation of DQ amino acid sequences strongly associated with IDDM in Japanese are discussed in this study, and contrasting results were found when such sequences were compared with those of Caucasians.Abbreviations used in this paper IDDM
insulin-dependent diabetes mellitus
- RFLP
restriction fragment length polymorphism
- Asp
aspartic acid
- Asp-57
aspartic acid at the 57th residue of the DQ chain
- non-Asp-57
nonaspartic acid at the 57th residue of the DQ chain
- R.R.
relative risk of Woolf and Haldane 相似文献
26.
Isamu Tanaka Akio Horie Joji Haratake Yasushi Kodama Kenzaburo Tsuchiya 《Biological trace element research》1988,16(1):19-26
There are few inhalation studies of nickel carcinogenesis. In this study, Wistar male rats were exposed to green nickel oxide
(NiO(G)) aerosols (mass median aerodynamic diameter, 0.6 μm) for 7 h/d, 5 d/wk for up to 12 mo. The average exposure concentration
was controlled at 0.3 and 1.2 mg/m3 during the exposure. For histopathological examination and measurement of the nickel concentration in rat organs, the rats
were sacrificed at 3, 6, and 12 mo of exposure and 8 mo clearance period following 12 mo of exposure.
The nickel content in rat lungs that was observed up to 2.6 mg after 12 mo exposure, was proportional to the exposure concentration
during the exposure. The clearance of the nickel from the lungs was very slow and the biological half time was determined
7.7 mo.
Although the rats were exposed continuously to NiO(G), for 12 mo and kept for 8 mo clearance period, there were no malignant
tumors in any of the exposed animals. 相似文献
27.
Satoru Furukawa Akio Ozaki Yukinobu Kotani Toshihide Nakanishi 《Applied microbiology and biotechnology》1988,29(2-3):253-257
Summary
l-Threonine hyper-producing mutants were obtained fromEscherichia coli W strain KY-8366, by reducingl-threonine degradation activity and enhancingl-threonine biosynthetic activity. Anl-threonine degradation reaction test using resting cells of KY-8366 suggested that the main pathway ofl-threonine degradation by KY-8366 is via glycine. A strain with reducedl-threonine degradation activity was obtained among those mutants that could not utilizel-threonine as sole nitrogen source. Rifampicin-resistant mutants andl-lysine plus methionine-insentitive mutants were isolated. These mutants showed enhanced aspartokinase levels and accumulated morel-threonine than the parental strains. Mutant H-4290 accumulated 58 g/l ofl-threonine. 相似文献
28.
Satoru Furukawa Akio Ozaki Toshihide Nakanishi 《Applied microbiology and biotechnology》1988,29(6):550-553
Summary Growth and l-threonine productivity of l-threonine producer Escherichia coli H-4290 were inhibited by precursor amino acids, l-homoserine and l-aspartate. l-Threonine hyper-producers were isolated among the mutants resistant to l-homoserine and l-aspartate. Mutants H-4351 (Homr) and H-4578 (Homr, Aspr) accumulated 22.2 g/l and 24.3 g/l of l-threonine in test tube cultures, while the parental strain H-4290 accumulated 18.2 g/l. The enzyme level of aspartokinase I (first enzyme of the threonine operon) was enhanced 2.3 times (H-4351) and 3 times (H-4578) that of H-4290. Mutant H-4578 accumulated 76 g/l of l-threonine in a 2-l jar fermentor after 75 h cultivation.Abbreviations DAP
diaminopimeric acid
- Met
l
poor growth in methionine-free medium
- AHV
-amino--hydroxyvaleric acid
- Thr-N-
lack of ability to utilize l-threonine as a nitrogen source
- Rif
rifampicin
- Lys+Metr
resistant to l-lysine and dl-methionine 相似文献
29.
Hormone autonomous callus was institutioniated reproduciblyon MS agar medium with 0.25 mg/liter of BA as the sole planthormone (AI medium) from young leaf explants of sugar beets.When leaf explants were inoculated into AI medium and culturedon a reciprocal shaker, single cells began to be released fromthe cut surfaces of the leaf pieces after 6 days, followed byactive release. When the single cells which had been releasedwere transferred to fresh liquid MS medium without any planthormones, they could divide and grow autonomously, giving riseto hormone-autonomous suspension cultures. The effects of BAon induction of hormone-autonomous cells are discussed. (Received March 12, 1987; Accepted October 13, 1987) 相似文献
30.
Anti-idiotypic antibodies against UV-induced tumor-specific CTL clones. Preparation in syngeneic combination 总被引:2,自引:0,他引:2
K Kuribayashi C Tanaka Y Matsubayashi T Masuda H Udono M Abe E Nakayama H Shiku 《Journal of immunology (Baltimore, Md. : 1950)》1988,141(11):4074-4080
In this study, we first established several CTL clones of (BALB/c x C57BL/6)F1 origin that were specific for either syngeneic UV female 1 or UV male 1 fibrosarcoma cell lines. All the CTL clones had Thy-1+ Lyt-2+ L3T4- phenotypes and showed Kd restriction when lysing the corresponding target cells. Sera obtained from syngeneic animals immunized with three CTL clones, 10B-5 for UV female 1, and CTL9 and CTL10 for UV male 1, showed specific inhibition of target cell lysis with the corresponding CTL clones. The inhibitory activities were found in sera of the majority of immunized animals. Because the inhibitory activity resides in protein A-binding fraction, mAb were produced by hybridizing spleen cells of hyperimmune animals. N1-56 was thus obtained from a mouse immunized with 10B-5 CTL clone reactive with UV female 1. N1-56 was clonotype specific, reacting with 10B-5 but not with other CTL lines or leukemia cell lines. No N1-56+ cells were detectable in thymocytes, lymph node cells, or spleen cells of either naive or UV female 1-immune CB6F1 mice. Immunoprecipitation showed that N1-56 reacts with 90,000 Mr molecules on 10B-5 CTL clone under nonreducing conditions and 45,000 Mr molecules under reducing conditions, indicating its reactivities with idiotypic determinants of TCR on the CTL clone. N1-56 inhibited lytic activity of 10B-5, but neither N1-56 nor alpha-10B-5 hyperimmune serum inhibited that of alpha-UV female 1 mixed lymphocyte tumor cell culture cells. N1-56 induced proliferation of 10B-5 without addition of Ag. 相似文献