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991.
M. Sang X. -C. Qin W. -D. Wang J. Xie X. -B. Chen K. B. Wang J. -P. Zhang L. -B. Li T. Y. Kuang 《Photosynthetica》2011,49(1):48-54
The generation of superoxide anion radical (O2
·−) in the cytochrome b
6
f complex (Cyt b
6
f) of spinach under high-light illumination was studied using electron paramagnetic resonance spectroscopy. The generation
of O2
·− was lost in the absence of molecular oxygen. It was also suppressed in the presence of NaN3 and could be scavenged by extraneous antioxidants such as ascorbate, β-carotene, and glutathione. The results also indicate that O2
·−, which is produced under high-light illumination of the Cyt b
6
f from spinach, might be generated from a reaction involing 1O2, and the Rieske Fe-S protein could serve as the electron donor in the O2
·− production. The mechanism of photoprotection of the Cyt b
6
f complex by antioxidants is discussed. 相似文献
992.
Chia-Hsuan Chen Hsiu-Lin Huang Mu-Tzu Chang Li-Chia Chiang Shih-Lin Cheng Bing-Tsan Liu Chih-Hua Wang Ming-Che Wu Mu-Chiou Huang 《Biologia》2011,66(6):1196-1201
The complete mitochondrial genome sequence of the Formosan sambar (Rusa unicolor swinhoei) was obtained by DNA sequencing based on PCR fragments amplified by 26 primer pairs designed by ourselves. The results indicated
that the mtDNA is 16,505 bp in size. This is the first report on mitochondrial DNA (mtDNA) sequence analysis of the Formosan
sambar and the sequence was deposited in the GenBank database under the accession number DQ989636. The complete mitochondrial
sequence included the following gene sequences: 12S and 16S rRNAs, 22 tRNAs and 13 protein-coding genes. The base composition
of the sequence was as follows: A, 33.51%; T, 28.97%; C, 24.07%; and G, 13.46%. The mitochondrial D-loop region was also analyzed
for comparative purposes in the Formosan sambar and 13 other species within the Cervidae family using neighbour-joining method.
The phylogenetic tree demonstrated that there are two separate groups, a European type and an Asian type, within the Cervidae
family. The D-loop sequences of mtDNA of 24 Formosan sambar animals were compared, and the results showed that the Formosan
sambar can be divided into two clades. 相似文献
993.
An acidic microenvironment induces disruption of adherens junctions (AJs) of hepatoma cells. This study investigated the impact of an acidic extracellular pH (pHe) on p120-catenin (p120-ctn) serine phosphorylation. pH 6.6 treatment increased intracellular calcium levels, activated protein kinase C (PKC)α and PKCδ, and decreased serine phosphorylation of p120-ctn. Further knockdown of PKCα and δ by small interference RNA (siRNA) prevented the pH 6.6-induced downregulation of p120-ctn at AJ and the serine dephosphorylation of p120-ctn. Moreover, PP2 pretreatment and siRNA of c-Src abrogated the pH 6.6-induced PKCδ activation. Together, the c-Src-PKCδ cascade and PKCα regulate the acidic pHe-induced AJ disruption. 相似文献
994.
995.
While sulfur dioxide (SO2) has been previously known for its toxicological effects, it is now known to be produced endogenously in mammals from sulfur-containing amino acid l-cysteine. l-cysteine is catalyzed by cysteine dioxygenase (CDO) to l-cysteinesulfinate, which converts to β-sulfinylpyruvate through transamination by aspartate aminotransferase (AAT), and finally spontaneously decomposes to pyruvate and SO2. The present study explored endogenous SO2 production, and AAT and CDO distribution in different rat tissue. SO2 content was highest in stomach, followed by tissues in the right ventricle, left ventricle, cerebral gray matter, pancreas, lung, cerebral white matter, renal medulla, spleen, renal cortex and liver. AAT activity and AAT1 mRNA expression were highest in the left ventricle, while AAT1 protein expression was highest in the right ventricle. AAT2 and CDO mRNA expressions were both highest in liver tissue. AAT2 protein expression was highest in the renal medulla, but CDO protein expression was highest in liver tissue. In all tissues, AAT1 and AAT2 were mainly distributed in the cytoplasm rather than the nucleus. These observed differences among tissues endogenously generating SO2 and associated enzymes are important in implicating the discovery of SO2 as a novel endogenous signaling molecule. 相似文献
996.
目的研究大鼠局灶性脑缺血再灌注损伤后神经元和星形胶质细胞表达量的动态演变及各自cyclin D1的表达差异。方法建立大鼠大脑中动脉阻塞(MCAO)再灌注模型,随机分为再灌注后1d组,3d组,7d组,14d组和假手术组,应用流式细胞术检测各组再灌注后不同时间点神经元和星形胶质细胞数量变化及各自cyclin D1的表达。结果缺血侧梗死边缘区皮质星形胶质细胞的表达增加,而神经元的表达下降,与假手术组比较有明显差异(P〈0.05);神经元和星形胶质细胞中各自cyclin D1的表达在再灌注7d、14d后表达上调,且星形胶质细胞中的cyclinD1增加更明显,与假手术组比较有统计学差异(P〈0.05)。结论大鼠脑缺血再灌注后,缺血侧梗死边缘区皮质星形胶质细胞和神经元的cyclinD1表达均有不同程度的上调,星形胶质细胞的cyclin D1表达上调比神经元的更为显著。 相似文献
997.
998.
999.
Xin Chen Jian Zhang Ji-Hua Liu Bo-Yang Yu 《Journal of Molecular Catalysis .B, Enzymatic》2008,54(3-4):72-75
The regioselective glycosylation of three isomers of hydroxybenzoic acids was observed in Panax ginseng hairy root cultures. p-Hydroxybenzoic acid (1) and m-hydroxybenzoic acid (2) were converted into their corresponding glycosides (1a and 2a) and glycosyl esters (1b and 2b) while no metabolite of o-hydroxybenzoic acid (3) was detected. A new compound, m-hydroxybenzoic acid β-d-xylopyranosyl (1 → 6)-β-d-glycopyranosyl ester (2c) was identified as a biotransformation product of 2. Further time-course studies of the biotransformation reactions showed that the glycosides were major products in the latter stage. The addition of carbohydrates or antioxidants increased glycosyl esters formation. 相似文献
1000.
The behavior of Na/K pump currents when exposed to an oscillating electric field is studied by computer simulation. The pump
current from a single pump molecule was sketched based on previous experimental results. The oscillating electric field is
designed as a symmetric, dichotomous waveform varying the membrane potential from −30 to −150 mV around the membrane resting
potential of −90 mV. Based on experimental results from skeletal muscle fibers, the energy needed to overcome the electrochemical
potentials for the Na and K-transports are calculated in response to the field’s two half-cycles. We found that a specially
designed oscillating electric field can eventually synchronize the pump molecules so that all the individual pumps run at
the same pumping rate and phase as the field oscillation. They extrude Na ions during the positive half-cycle and pump in
K ions during the negative half-cycle. The field can force the two ion-transports into the corresponding half-cycles, respectively,
but cannot determine their detailed positions. In other words, the oscillating electric field can synchronize pumps in terms
of their pumping loops but not at a specific step in the loop. These results are consistent with our experimental results
in measurement of the pump currents. 相似文献