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排序方式: 共有719条查询结果,搜索用时 140 毫秒
1.
Hiroshi Iwasaki Toshikazu Shiba Atsuo Nakata Hideo Shinagawa 《Molecular & general genetics : MGG》1989,219(1-2):328-331
Summary The ruv operon of Escherichia coli consists of two genes, orfl1 and ruv, which encode 22 and 37 kilodalton proteins, respectively, and are regulated by the SOS system. Although the distal gene, ruv, is known to be involved in DNA repair, the function of orf1 has not been studied. To examine whether orf1 is also involved in DNA repair, we constructed a strain with a deletion of the entire ruv operon. The strain was sensitive to UV even after introduction of low copy number plasmids carrying either orf1 or ruv, but UV resistance was restored by introduction of a plasmid carrying both orfl and ruv. These results suggest that orf1 as well as ruv is involved in DNA repair. Therefore, orf1 and ruv should be renamed ruvA and ruvB, respectively. 相似文献
2.
1. The working hypothesis that neuropeptide gene expression in a neuron is an indicator of that neuron's physiological activity is discussed. 2. Representative examples from the literature are presented to support the hypothesis. 3. Further, we discuss the regulation of expression of two opioid peptides, preproenkephalin and preprodynorphin, in laminae I and II of the spinal cord and in nucleus caudalis of the trigeminal nuclear complex, where they may play a role in pain modulation. 4. The expression of the opioid peptide genes can be induced by both painful and nonnoxious stimuli in neurons in time-dependent and sensory-specific fashions. 相似文献
3.
The uptake of sorbitol into vacuoles from immature flesh ofapple fruit (Maluspumila Mill, var domestica Schneid.) was facilitatedby 106 M ABA, while such uptake into protoplasts wasnot stimulated. By contrast, the application of 105 MIAA facilitated uptake of sorbitol into protoplasts but didnot significantly into vacuoles. (Received July 17, 1990; Accepted December 25, 1990) 相似文献
4.
Ryuji Fukuda Ryoji Yano Toshikazu Fukui Toshiharu Hase Akira Ishihama Hiroshi Matsubara 《Molecular & general genetics : MGG》1985,201(2):151-157
Summary In order to clone the Escherichia coli gene for the stringent starvation protein (SSP), we determined its N-terminal sequence as well as the sequence of two peptide fragments obtained by cyanogen bromide cleavage of the protein. We then chemically synthesized four sets of oligodeoxyribonucleotide mixtures that represented possible codon combinations for parts of these amino acid sequences. The synthetic oligonucleotides were labelled with 32P at their 5-termini and used as hybridization probes to detect DNA fragments containing the complementary sequences. Genomic Southern hybridization of E. coli chromosomal DNA gave up to ten DNA fragments hybridizing with each probe but only a few hybridized with two or more of the probes. The latter fragments were coloned in pBR322. By determining partial base sequences with a rapid method and examining proteins encoded by the DNA fragments, we were able to show that we had isolated a clone containing the complete SSP structural gene.Abbreviations SSP
stringent starvation protein
- PTH
phenylthiohydantoin 相似文献
5.
Growth and other characteristics of a cell line (SP-8) established from Shope virus-induced cutaneous papilloma of domestic rabbit 总被引:1,自引:0,他引:1
6.
Antioxidant Properties of Bromocriptine, a Dopamine Agonist 总被引:3,自引:1,他引:2
Toshikazu Yoshikawa† Yukiko Minamiyama Yuji Naito Motoharu Kondo 《Journal of neurochemistry》1994,62(3):1034-1038
Abstract: It has been suggested that free radicals may adversely influence the pathogenesis of Parkinson's disease. We conducted this study to determine whether bro-mocriptine, an agent widely used for treating parkinsonism, possesses antioxidant effects. Bromocriptine scavenged superoxide produced from a superoxide generating system (hypoxanthine-xanthine oxidase) by the spin-trapping method using electron spin resonance. Bromocriptine had a strong scavenging effect on the 5,5-dimethyl-1-pyrroline- N -oxide hydroxide signal produced from Fenton's reaction. Bromocriptine also attenuated the stable free radical diphenyl- p -picrylhydrazyl signal. This drug inhibited the autooxidation of rat brain homogenates in a dose-dependent manner in vitro. Autooxidation of brain homogenates collected from rats treated with bromocriptine (2.5 mg/kg, i.p., daily for 3 days) was significantly reduced as compared with values in untreated rat homogenates. These observations suggest that bromocriptine is a free radical scavenger and a potent antioxidant. 相似文献
7.
8.
Yoichi Honda Toshikazu Irie Mina Atsuji Takashi Watanabe Masaaki Kuwahara 《Mycoscience》1996,37(4):459-461
To develop a dominant genetic marker inPleurotus ostreatus, mutant strains resistant to a carboxin-derived fungicide, flutolanil, were isolated. These mutants included strains which
showed resistance to 50-fold higher concentration of fluotolanil than the wild-type strain, even after successive cultivations
in the absence of the drug. Dominance of the phenotype was confirmed by back-crossing between the resistant and wild-type
monokaryons. The flutolanilresistance was also shown to be stably inherited by the basidiospore-derived progenies of the mutant
strains. 相似文献
9.
Keith L. Constantine Mark S. Friedrichs David Detlefsen Maki Nishio Mitsuaki Tsunakawa Tamotsu Furumai Hiroaki Ohkuma Toshikazu Oki Susan Hill Robert E. Bruccoleri Pin-Fang Lin Luciano Mueller 《Journal of biomolecular NMR》1995,5(3):271-286
Summary The 21-amino acid peptides siamycin II (BMY-29303) and siamycin I (BMY-29304), derived from Streptomyces strains AA3891 and AA6532, respectively, have been found to inhibit HIV-1 fusion and viral replication in cell culture. The primary sequence of siamycin II is CLGIGSCNDFAGCGYAIVCFW. Siamycin I differs by only one amino acid; it has a valine residue at position 4. In both peptides, disulfide bonds link Cys1 with Cys13 and Cys7 with Cys19, and the side chain of Asp9 forms an amide bond with the N-terminus. Siamycin II, when dissolved in a 50:50 mixture of DMSO and H2O, yields NOESY spectra with exceptional numbers of cross peaks for a peptide of this size. We have used 335 NOE distance constraints and 13 dihedral angle constraints to generate an ensemble of 30 siamycin II structures; these have average backbone atom and all heavy atom rmsd values to the mean coordinates of 0.24 and 0.52 Å, respectively. The peptide displays an unusual wedge-shaped structure, with one face being predominantly hydrophobic and the other being predominantly hydrophilic. Chemical shift and NOE data show that the siamycin I structure is essentially identical to siamycin II. These peptides may act by preventing oligomerization of the HIV transmembrane glycoprotein gp41, or by interfering with interactions between gp41 and the envelope glycoprotein gp120, the cell membrane or membrane-bound proteins [Frèchet, D. et al. (1994) Biochemistry, 33, 42–50]. The amphipathic nature of siamycin II and siamycin I suggests that a polar (or apolar) site on the target protein may be masked by the apolar (or polar) face of the peptide upon peptide/protein complexation.Abbreviations ABNR
adopted basis Newton Raphson
- AIDS
acquired immunodeficiency syndrome
- CW
continuous wave
- DMSO
dimethylsulfoxide
- DQF-COSY
two-dimensional double-quantum-filtered correlation spectroscopy
- HIV
human immunodeficiency virus
- HSQC
heteronuclear single-quantum coherence
- NOE
nuclear Overhauser enhancement
- NOESY
two-dimensional nuclear Overhauser enhancement spectroscopy
- ppm
parts per million
- P.E.-COSY
two-dimensional primitive exclusive correlation spectroscopy
- REDAC
redundant dihedral angle constraint
- rf
radio frequency
- rmsd
root-mean-square difference
- SIV
simian immunodeficiency virus
- sw
spectral width
- m
mixing time
- TOCSY
two-dimensional total correlation spectroscopy
- TSP
trimethylsilyl-2,2,3,3-2H4-propionate
- 2D
two-dimensional 相似文献
10.
Yukio Takahata Toshikazu Hasegawa Toshisada Nishida 《International journal of primatology》1984,5(3):213-233
Fifty-four episodes of predatory behavior of wild chimpanzees were recorded in Mahale, western Tanzania, from August 1979
to May 1982. The chimpanzees most frequently hunt in two seasons, during May, and from August to December. Longer-term fecal
analysis indicates that predation frequency is significantly higher in the dry than in the rainy season. The seasonality of
predation might be the result of the sum of various ecological factors, at least one of which is the birth season of the prey
species. Most of the prey are juvenile blue duiker, bushbuck, bushpig, red colobus, and red-tailed monkeys. Sex difference
is recognized in the prey selection and in the hunting method employed. Apparent local difference in the predatory behavior
between Mahale and Combe chimpanzees (in Mahale,females hunt more frequently, and blue duiker is the most frequent prey) can be understood in terms of the difference either
in the observation methods or in the faunal diversity and density. Other aspects of predatory behavior also are reported. 相似文献