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61.
Kudo S Caaveiro JM Miyafusa T Goda S Ishii K Matsuura T Sudou Y Kodama T Hamakubo T Tsumoto K 《Molecular bioSystems》2012,8(8):2050-2053
Human P-cadherin is a promising therapeutic target against cancer. However, its characterization at the molecular level is still lacking. We report that human P-cadherin associated irreversibly in a distinct dimer configuration. Unexpectedly, the divalent cation Ca2? was not necessary for dimerization, although it greatly stabilized the protein-protein complex. 相似文献
62.
Yuko Mogi Yayoi Kagami Kazuyoshi Kuwano Shinichi Miyamura Tamotsu Nagumo Shigeyuki Kawano 《Journal of phycology》2008,44(5):1290-1299
Gametes of the marine green alga Ulva compressa L. are biflagellate and pear shaped, with one eyespot at the posterior end of the cell. The species is at an early evolutionary stage between isogamy and anisogamy. In the past, zygote formation of green algae was categorized solely by the relative sizes of gametes produced by two mating types (+ and ?). Recently, however, locations of cell fusion sites and/or mating structures of gametes have been observed to differ between mating types in several green algae (asymmetry of cell fusion site and/or mating structure positions). To use this asymmetry for determining gamete mating type, we explored a new method, field emission scanning electron microscopy (FE‐SEM), for visualizing the mating structure of U. compressa. When gametes were subjected to drying stress in the process of a conventional critical‐point‐drying method, a round structure was observed on the cell surfaces. In the mating type MGEC‐1 (mt+), this structure was located on the same side of the cell as the eyespot, whereas it was on the side opposite the eyespot in the mating type MGEC‐2 (mt?). The gametes fuse at the round structures. TEM showed an alignment of vesicles inside the cytoplasm directly below the round structures, which are indeed the mating structures. Serial sectioning and three‐dimensional construction of TEM micrographs confirmed the association of the mating structure with flagellar roots. The mating structure was associated with 1d root in the MGEC‐1 gamete but with 2d root in the MGEC‐2 gamete. 相似文献
63.
Kawahara M Obata Y Sotomaru Y Shimozawa N Bao S Tsukadaira T Fukuda A Kono T 《Nature protocols》2008,3(2):197-209
A reliable nuclear transfer method was first reported in 1983; it provided definite evidence that parthenogenetic embryos are lethal at early postimplantation in mammals. Subsequently, nuclear transfer has been extensively used as an important and versatile tool for investigating embryo and somatic-cell cloning and nucleo-cytoplasmic interactions. Further development of this technique has enabled the generation of bimaternal embryos containing two haploid sets of maternal genomes from female germ cells of different origins. By using a 2-d nuclear transfer system for oocyte reconstruction, viable mice can be produced solely from maternal genomes, without the participation of the paternal genome. This oocyte reconstruction system, as described in this protocol, could provide valuable guidelines for exploring the potential endowments of gametes and for conferring novel properties to them. 相似文献
64.
Goda HM Ushigusa K Ito H Okino N Narimatsu H Ito M 《Biochemical and biophysical research communications》2008,375(4):441-446
We report here the molecular cloning, expression and characterization of a novel endo-alpha-N-acetylgalactosaminidase, classified into the GH101 family, from Enterococcus faecalis (endo-EF). The recombinant endo-EF was found to catalyze the liberation of core1-disaccharides (Galbeta1-3GalNAc) from core1-pNP (Galbeta1-3GalNAcalpha-pNP) like other GH101 family enzymes. However, endo-EF seems to differ in specificity from the GH101 enzymes reported to date, because it was able to release trisaccharides from core2-pNP (Galbeta1-3[GlcNAcbeta1-6]GalNAcalpha-pNP) and tetrasaccharides from Gal-core2-pNP (Galbeta1-3[Galbeta1-3GlcNAcbeta1-6]GalNAcalpha-pNP). Interestingly, the enzyme could transfer not only core1-disaccharides but also core2-trisaccharides to alkanols generating alkyl-oligosaccharides. Endo-EF should facilitate O-glycoprotein research. 相似文献
65.
Unregulated expression of the imprinted genes H19 and Igf2r in mouse uniparental fetuses. 总被引:1,自引:0,他引:1
Yusuke Sotomaru Yukiko Katsuzawa Izuho Hatada Yayoi Obata Hiroyuki Sasaki Tomohiro Kono 《The Journal of biological chemistry》2002,277(14):12474-12478
The present study shows that the H19 and Igf2r genes, which are imprinted and expressed solely from maternal alleles, are expressed in an unregulatable manner in mouse uniparental, androgenetic, and parthenogenetic fetuses at day 9.5 of gestation. In the androgenetic fetuses, the H19 and Igf2r genes were respectively expressed at 12 and 40% of the levels in biparental fetuses. In addition, the expression of both genes was excessive (1259 and 482%, respectively) in the parthenotes. These expressions of the imprinted genes were not regulated by methylation in the regulatory regions. Moreover, the expression of the antisense Igf2r RNA (Air) was also excessive and was not correlated with Igf2r gene expression in the uniparental fetuses. Taken together, these results indicate that the parental specific expression of imprinted genes is not maintained in particular genes in uniparental embryos, which in turn suggests that both parental genomes are required to establish maternal specific expression of the H19 and Igf2r genes by trans-acting mechanisms. 相似文献
66.
Takashi Manabe Kiyoshi Goda Tokuji Kimura 《Biochimica et Biophysica Acta (BBA)/General Subjects》1976,428(2):312-320
The reaction of triphenyl phosphine to iron-sulfur proteins from adrenal cortex mitochondria, spinach chloroplasts, and Clostridium pasteurianum was investigated. As ethanol concentrations in the reaction mixture increased, the rate of the reaction decreased. In the simultaneous presence of 1 M KCl and 5 M urea, the reaction rate reached at maximum. Under these conditions the initial rates of the decolorization reaction by the phosphine were found to be 8.7, 0.88, and 1.8 nmol of ferrodoxin per min at 25°C for adrenal, spinach, and clostridial ferredoxins, respectively. The kinetic curves for the reaction of the phosphine sulfide formation, the loss of labile sulfur, and the deterioriation of visible absorption showed a similar pattern with a comparable rate. During this reaction, the complete reduction of ferric ions present in ferredoxin was observed with a fast rate under either aerobic or anaerobic conditions.These results suggest that the iron atoms in ferredoxin are first reduced by the intramolecular reductants in the presence of triphenyl phosphine with the concomitant formation of S22?, which then reacts with triphenyl phosphine resulting in the formation of triphenyl phosphine sulfide. 相似文献
67.
68.
Measurement of PO2 in liver using EPR oximetry 总被引:1,自引:0,他引:1
Jiang J.; Nakashima T.; Liu K. J.; Goda F.; Shima T.; Swartz H. M. 《Journal of applied physiology》1996,80(2):552-558
69.
Fumonisins B1(FB1) and B2(FB2) were isocratically separated on a fluorocarbon column without using an ion pair reagent and nonvolatile buffer during the
HPLC and were detected by an o-phthalaldehyde postcolumn derivatization system using a fluorescence detector. The minimum detectable concentrations of FB1 and FB2 in corn by this system were 0.01 μg/g and 0.01 μg/g, respectively. The separated fumonisins were further identified by a
directly interfaced ion trap MS using electrospray ionization. FB1 and FB2 in naturally contaminated corn were identified in the selective ion monitoring mode at concentrations of 3.75μg/g and 1.44
μg/g, respectively.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
70.
The reproductive allocation (allocation of net production to acorns) of a tall tree speciesQuercus serrata was estimated by a method combining branch diameter distribution and the sampling of acorns per branch. Acorn production
per branch of 0.5-cm diameter significantly varied among individuals and years, but not significantly across tree size. Leaf
production per branch of 0.5-cm diameter had little annual fluctuation, while that of acorns fluctuated about 6 times between
the maximum and minimum. The reproductive allocation was regressed against vegetative allocation, following the general model
of klinkhameret al. (1992); the reproduction had a beginning threshold and reproductive allocation increased drastically at relatively young
stage after the tree began reproduction. With its small threshold production, coppicing traits and large maximum size,Q. serrata seemed adaptive to infrequent but large-scale disturbances like fires. 相似文献