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81.
Han SY Inoue H Terada T Kamoda S Saburi Y Sekimata K Saito T Kobayashi M Shinozaki K Yoshida S Asami T 《Journal of enzyme inhibition and medicinal chemistry》2003,18(3):279-283
Lignostilbene-alpha,beta-dioxygenase (LSD, EC 1.13.11.43) is involved in oxidative cleavage of the central double bond of lignostilbene to form the corresponding aldehydes by a mechanism similar to those of 9-cis-epoxycarotenoid dioxygenase and beta-carotene 15,15'-dioxygenase, key enzymes in abscisic acid biosynthesis and vitamin A biosynthesis, respectively. In this study, several N-benzylideneanilines and amine were synthesized and examined for their efficacy as inhibitors of LSD. N-(4-Hydroxybenzylidene)-3-methoxyaniline was found to be a potent inhibitor with IC50 = 0.3 microM and N-(4-hydroxybenzyl)-3-methoxyaniline was also active with IC50 = 10 microM. The information obtained from the structure-activity relationships study here can aid in discovering inhibitors of both abscisic acid and vitamin A biosynthesis. 相似文献
82.
NRSF regulates the fetal cardiac gene program and maintains normal cardiac structure and function 总被引:1,自引:0,他引:1
83.
Miho Iijima Kazuhiro Aiba Yoshimasa Tanaka Hideko Urushihara 《Journal of plant research》1998,111(1):93-96
Two cDNA fragments induced in developing zygotes ofDictyostelium discoideum were isolated by mRNA differential display. the relevant genes were also found to be expressed during asexual development,
suggesting that sexual and asexual development share common molecular mechanisms inD. discoideum. 相似文献
84.
Fujito Kageyama Yoshimasa Kobayashi Gou Murohisa Erina Shimizu Fumitaka Suzuki Masataka Kikuyama Kenichi Souda Tsunehisa Kawasaki Hirotoshi Nakamura 《Biological trace element research》1998,64(1-3):185-196
Recent reports suggest the hepatic iron concentration (HIC) may influence the activity of hepatitis and the response to interferon
(IFN) therapy in patients with chronic hepatitis C (CH-C). We have evaluated iron status in 28 patients with CH-C and determined
if pretreatment iron status can predict the response to IFN-α therapy in these patients. Increased serum iron, transferrin
saturation, and ferritin levels were observed in 3 (11%), 11 (39%), and 5 (18%) patients, respectively. Hepatic iron deposits
were histologically detected in 17 (61%) patients, and 14 of them had stainable hepatocytic iron. However, all HIC values
were within the normal range (203–1279 μg/g). Seven of 17 patients treated with IFN-α for 6 mo had normalization of serum
transaminases and disappearance of serum HCV-RNA (responders). Nonresponders had a significantly higher median HIC compared
with responders (710 vs 343 μg/g, respectively;p < 0.05). There was no significant difference in other pretreatment iron parameters, serum HCV-RNA level, or HCV-genotype between
responders and nonresponders. In conclusion, mild hepatic iron accumulation occurs in patients with CH-C. Increased hepatic
iron stores are associated with poor response to IFN therapy. Pretreatment HIC may be an additional host-specific parameter
with a predictive value for responsiveness to IFN therapy, in addition to well-known predictive viral factors. 相似文献
85.
Yoshimasa Takizawa Yong Qing Motoki Takaku Takako Ishida Yuichi Morozumi Takashi Tsujita Toshiaki Kogame Kouji Hirota Masayuki Takahashi Takehiko Shibata Hitoshi Kurumizaka Shunichi Takeda 《Nucleic acids research》2010,38(15):5059-5074
RAD51 is a key factor in homologous recombination (HR) and plays an essential role in cellular proliferation by repairing DNA damage during replication. The assembly of RAD51 at DNA damage is strictly controlled by RAD51 mediators, including BRCA1 and BRCA2. We found that human RAD51 directly binds GEMIN2/SIP1, a protein involved in spliceosome biogenesis. Biochemical analyses indicated that GEMIN2 enhances the RAD51–DNA complex formation by inhibiting RAD51 dissociation from DNA, and thereby stimulates RAD51-mediated homologous pairing. GEMIN2 also enhanced the RAD51-mediated strand exchange, when RPA was pre-bound to ssDNA before the addition of RAD51. To analyze the function of GEMIN2, we depleted GEMIN2 in the chicken DT40 line and in human cells. The loss of GEMIN2 reduced HR efficiency and resulted in a significant decrease in the number of RAD51 subnuclear foci, as observed in cells deficient in BRCA1 and BRCA2. These observations and our biochemical analyses reveal that GEMIN2 regulates HR as a novel RAD51 mediator. 相似文献
86.
Nakazawa Y Sagane Y Kikuchi T Uchino M Nagai T Sato H Toeda K Takano K 《The protein journal》2010,29(8):598-608
We previously isolated Streptomyces racemochromogenes strain 10-3, which produces a phospholipase D (PLD) with high transphosphatidylation activity. Here, we purified and cloned
the PLD (PLD103) from the strain. PLD103 exerted the highest hydrolytic activity at a slightly alkaline pH, which is in contrast
to the majority of known Streptomyces PLDs that have a slightly acidic optimum pH. PLD103 shares only 71–76% amino acid sequence identity with other Streptomyces PLDs that have a slightly acidic optimum pH; thus, the diversity in the primary structure might explain the discrepancy observed
in the optimum pH. The purified PLD displayed high transphosphatidylation activity in the presence of glycerol, l-serine, and 2-aminoethanol hydrochloride with a conversion rate of 82–97% in a simple one-phase system, which was comparable
to the rate of other Streptomyces PLDs in a complicated biphasic system. 相似文献
87.
Exogenous proline mitigates the detrimental effects of salt stress more than exogenous betaine by increasing antioxidant enzyme activities 总被引:3,自引:0,他引:3
Hoque MA Okuma E Banu MN Nakamura Y Shimoishi Y Murata Y 《Journal of plant physiology》2007,164(5):553-561
Proline and betaine accumulate in plant cells under environmental stresses including salt stress. Here, we investigated effects of proline and betaine on the growth and activities of antioxidant enzymes in tobacco Bright Yellow-2 (BY-2) culture cells in suspension under salt stress. Both proline and betaine mitigated the inhibition of growth of BY-2 cells under salt stress and the mitigating effect of proline was more than that of betaine. Salt stress significantly decreased the activities of superoxide dismutase (SOD), catalase and peroxidase in BY-2 cells. Exogenous application of proline or betaine alleviated the reduction in catalase and peroxidase activities but not SOD activity under salt stress. In addition, proline was found to be effective in alleviating the inhibition of salt stress-induced catalase and peroxidase activities in BY-2 cells. Neither proline nor betaine directly scavenged superoxide (O(2)(-)) or hydrogen peroxide (H(2)O(2)). It is concluded that exogenous proline mitigates the detrimental effects of salt stress more than exogenous betaine because of its superior ability to increase the activities of antioxidant enzymes. 相似文献
88.
Hoque MA Banu MN Okuma E Amako K Nakamura Y Shimoishi Y Murata Y 《Journal of plant physiology》2007,164(11):1457-1468
Up-regulation of the antioxidant system provides protection against NaCl-induced oxidative damage in plants. Antioxidants and activity of enzymes involved in the ascorbate-glutathione (ASC-GSH) cycle in tobacco Bright Yellow-2 (BY-2) were investigated to assess the antioxidant protection offered by exogenous proline and glycinebetaine (betaine from now on) against salt stress using cells grown in suspension culture. Reduced ascorbate (ASC) was detected in BY-2 cells but dehydroascorbate (DHA) was not. Large quantities of a reduced form of glutathione (GSH) and smaller quantities of an oxidized form of glutathione (GSSG) were detected in BY-2 cells. Salt stress significantly reduced the contents of ASC and GSH as well as activities of ASC-GSH cycle enzymes such as ascorbate peroxidase (APX), monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), and glutathione reductase (GR). Exogenous proline or betaine increased the activities of all enzymes except MDHAR involved in NaCl-induced ASC-GSH cycle. Levels of ASC and GSH in BY-2 cells under salt stress were lower in the presence of proline or betaine than in the absence of proline or betaine whereas there was no difference in redox status. Proline proved more effective than betaine in maintaining the activity of enzymes involved in NaCl-induced ASC-GSH cycle. Neither proline nor betaine had any direct protective effect on NaCl-induced enzyme activity involved in the antioxidant system; however, both improved salt tolerance by increasing enzyme activity. The present study, together with our earlier findings [Hoque MA, Okuma E, Banu MNA, Nakamura Y, Shimoishi Y, Murata Y. Exogenous proline mitigates the detrimental effects of salt stress more than exogenous betaine by increasing antioxidant enzyme activities. J Plant Physiol 2006;164:553-61.], suggests that proline offered greater protection against salt stress than betaine did because proline was more effective in increasing the activity of enzymes involved in the antioxidant system. 相似文献
89.
Social conditions and function of inter-group movement of females of the polygynous goby, Trimma okinawae, have been studied at Akamizu Beach, Kagoshima, Japan. Some females moved from their original groups, where the male was
still present, to other groups. Before the movement females sometimes temporarily visited the group into which they subsequently
moved, suggesting they were able to assess social conditions during the visit. By moving, the females increased in size rank
or escaped from similar-sized female competitors in their previous groups. Although the social ranks of the moving females
in their original groups were lower than those of the resident females, the ratio of the number of females that changed sex
to the number of females surviving at the end of the study did not differ for the two types of female. Inter-group movement
of females may increase the probability of their changing sex to become a dominant male. 相似文献
90.
Dietary flavonoid apigenin is a potential inducer of intracellular oxidative stress: the role in the interruptive apoptotic signal 总被引:1,自引:0,他引:1
Miyoshi N Naniwa K Yamada T Osawa T Nakamura Y 《Archives of biochemistry and biophysics》2007,466(2):274-282
Apigenin is a representative dietary flavone (2-phenyl-4H-1-benzopyran-4-one) inhibiting cancer cell growth both in cell culture systems and in vivo. The prooxidant potential of apigenin was confirmed by the observations using flowcytometric and immunoblotting techniques that the intracellular accumulations of reactive oxygen species (ROS) and protein carbonyls were detected in the cells treated with apigenin in a dose-dependent manner. Conversely, chrysin (5,7-dihydroxyflavone) did not show any prooxidant effect. A structure-activity relationship data thus indicated that a 4'-monohydroxyl group, which can be oxidized to semiquinone radical but not up to quinone-like metabolite, is essential for prooxidant effect. When HL-60 cells were treated with not only a heme synthesis inhibitor succinyl acetone (SA) but also myeloperoxidase (MPO) inhibitors, the ROS level enhanced by apigenin was significantly reduced. The gathered data suggested that peroxidase-catalyzed production of apigenin B-ring phenoxyl radicals might be responsible for the prooxidant effect. This is supported by the observation that MPO is able to catalyze production of apigenin phenoxyl radicals, detected by an electron spin resonance-spin trapping technique. We also reveal that both SA and alpha-tocopherol enhance cellular susceptibility to apoptosis-inducing stimuli by apigenin. In conclusion, the prooxidant effect of apigenin is likely to oxidize a variety of thiols through the formation of phenoxyl radicals and thus seems to play a significant role in the abortive apoptotic pathway switching to necrotic cell death. 相似文献