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191.
We investigated the effects of estradiol-treated females on the behavior of male budgerigars. In comparison to control females,
females given implants of estradiol showed elevated nest behavior and darker cere color, which are characteristics of breeding
females. After we confirmed the efficacy of estradiol treatment on behavior and morphology, each female was paired with a
male mate. Males paired with estradiol-treated females showed more courtship behavior (auditory and visual display, and courtship
feeding) to their mates than males paired with control females. These data indicate that budgerigar females with a high estrogen
level enhance males' courtship behavior. Since males did not show response to estradiol-treated females soon after females
were introduced, effects of estradiol-treated female budgerigars may be mediated by the endocrine system, rather than wholly
by the nervous system, of males.
Electronic Publication 相似文献
192.
193.
Kubota T Tokuno K Nakagawa J Kitamura Y Ogawa H Suzuki Y Suzuki K Oka K 《Biochemical and biophysical research communications》2003,303(1):332-336
Mg(2+) buffering mechanisms in PC12 cells were demonstrated with particular focus on the role of the Na(+)/Mg(2+) transporter by using a newly developed Mg(2+) indicator, KMG-20, and also a Na(+) indicator, Sodium Green. Carbonyl cyanide p-(trifluoromethoxy) phenylhydrazone (FCCP), a protonophore, induced a transient increase in the intracellular Mg(2+) concentration ([Mg(2+)](i)). The rate of decrease of [Mg(2+)](i) was slower in a Na(+)-free extracellular medium, suggesting the coupling of Na(+) influx and Mg(2+) efflux. Na(+) influxes were different for normal and imipramine- (a putative inhibitor of the Na(+)/Mg(2+) transporter) containing solutions. FCCP induced a rapid increase in [Na(+)](i) in the normal solution, while the increase was gradual in the imipramine-containing solution. The rate of decrease of [Mg(2+)](i) in the imipramine-containing solution was also slower than that in the normal solution. From these results, we show that the main buffering mechanism for excess Mg(2+) depends on the Na(+)/Mg(2+) transporter in PC12 cells. 相似文献
194.
Suzuki R Nagata K Yumoto F Kawakami M Nemoto N Furutani M Adachi K Maruyama T Tanokura M 《Journal of molecular biology》2003,328(5):1149-1160
Here we report the solution structure of an archaeal FK506-binding protein (FKBP) from a thermophilic archaeum, Methanococcus thermolithotrophicus (MtFKBP17), which has peptidyl prolyl cis-trans isomerase (PPIase) and chaperone-like activities, to reveal the structural basis for the dual function. In addition to a typical PPIase domain, a newly identified domain is formed in the flap loop by a 48-residue insert that is required for the chaperone-like activity. The new domain, called IF domain (the Insert in the Flap), is a novel-folding motif and exposes a hydrophobic surface, which we consider to play an important role in the chaperone-like activity. 相似文献
195.
Y Shinoda A Shouji T Yamane A Suzuki T Ashida H Kihara M Ohno 《Journal of biochemistry》1990,107(1):84-86
Crystallization and a preliminary crystallographic study of Trimeresurus flavoviridis (habu snake) phospholipase A2 (PLA2) were carried out. Although crystals were obtained from various solutions, crystals suitable for X-ray analysis could be obtained from polyethylene glycol solutions only when a repeated seeding technique was applied starting from twinned crystals. The crystal is monoclinic with space group P21, with a = 44.1, b = 55.7, c = 48.8 A, and beta = 92.4 degrees. An asymmetric unit contains a dimer consisting of two identical subunits made of 122 amino acids. The crystal reflects X-rays beyond 2.5 A. A Pt derivative gave a good isomorphous crystal. 相似文献
196.
Shinji Takamatsu Toshiyuki Katsumata Noboru Inoue Toshinori Watanabe Yasuhisa Fujibayashi Makoto Takeuchi 《Glycoconjugate journal》2003,20(7-8):473-481
Over the past two decades, sugar chain structures of human chorionic gonadotropin (hCG) produced in healthy people, three types of trophoblastic disease, and some types of cell lines have been analyzed. The abnormal biantennary structure of hCG is a good marker for the diagnosis of malignant choriocarcinoma. In spite of much research, hCG with an abnormal biantennary structure is only detected in the urine of choriocarcinoma or pregnant diabetic patients. We hypothesized that the formation mechanism of the abnormal biantennary sugar chain structure is mainly caused by high GnT-IV activity. To confirm this, we measured the N-acetylglucosaminyltransferase (GnT)-IV activity and hCG productivity in three choriocarcinoma cell lines, and selected JEG-3 cells. hCG samples were purified from medium conditioned by JEG-3 cells, and their sugar chain structures were analyzed. We detected an abnormal biantennary structure, and the proportions were different from those previously reported in the urine samples of choriocarcinoma patients. These findings proved our hypothesis and suggest the usefulness of JEG-3 cells for further analyses of abnormal biantennary structure formation. Published in 2004. 相似文献
197.
Mitsuhide Hamaguchi Hironari Kamikubo Kayo N. Suzuki Yoshihisa Hagihara Itaru Yanagihara Ikuhiro Sakata Mikio Kataoka Daizo Hamada 《PloS one》2013,8(8)
Enterohaemorrhagic E. coli (EHEC) induces actin reorganization of host cells by injecting various effectors into host cytosol through type III secretion systems. EspB is the natively partially folded EHEC effector which binds to host α-catenin to promote the actin bundling. However, its structural basis is poorly understood. Here, we characterize the overall structural properties of EspB based on low-resolution structural data in conjunction with protein dissection strategy. EspB showed a unique thermal response involving cold denaturation in the presence of denaturant according to far-UV circular dichroism (CD). Small angle X-ray scattering revealed the formation of a highly extended structure of EspB comparable to the ideal random coil. Various disorder predictions as well as CD spectra of EspB fragments identified the presence of α-helical structures around G41 to Q70. The fragment corresponding to this region indicated the thermal response similar to EspB. Moreover, this fragment showed a high affinity to C-terminal vinculin homology domain of α-catenin. The results clarified the importance of preformed α-helix of EspB for recognition of α-catenin. 相似文献
198.
199.
Kunitoyo Shibuya Michio Tanaka Takeo Nanbata Kiyoshi Isono Saburo Suzuki 《Bioscience, biotechnology, and biochemistry》2013,77(7):1229-1236
Polyoxins D, E, and F which possess 5-carboxyuracil as the nucleobase were reacted selectively with sodium bisulfite at pH 4.0 resulting in facile decarboxylation to afford corresponding 5,6-dihydrouracil-6-sulfonates and uracil type polyoxins (polyoxins L, M, and K) in good yield. The former compounds were also converted to the latter almost quantitatively with mild alkali treatment. Biological activities of the transformed compounds were described. 相似文献
200.
Two distinct forms of β-glucosidase, A and B, were found to occur in the cells of Pseudomonas fluorescens var. cellulosa : A was membrane-bound, while B cytosolic. They differed also from each other in some properties, such as molecular size, kinetic parameters, and susceptibility to various compounds. β-Glucosidase B was partially purified and studied especially of its substrate specificity. The results indicated that it may be an atypical β-glucosidase which possesses a certain character of exo-cellulase. 相似文献