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排序方式: 共有836条查询结果,搜索用时 14 毫秒
821.
Asako Narai-Kanayama Kosuke Saruwatari Natsumi Mori 《Bioscience, biotechnology, and biochemistry》2018,82(3):466-475
Black tea is a highly popular beverage, and its pigments, polymerized catechins such as theaflavins (TFs), are attracting attention due to their beneficial health effects. In this study, to test the inhibitory activities of TFs on the intestinal absorption of cholesterol, we investigated their effects on phosphatidylcholine (PC) vesicles in the absence or presence of a bile salt. (?)-Epicatechin gallate, (?)-epigallocatechin gallate, and TFs formed insoluble complexes with PC vesicles. Galloylated TFs such as TF2A, TF2B, and TF3 precipitated far more than other polyphenols. The subsequent addition of taurocholate redispersed the polyphenol-PC complexes, except that a large amount of TF2A remained insoluble. After incubation with taurocholate-PC micelles, TF2A elevated the turbidity of the micelle solution, providing red sediments. The TF2A-specific effect was dependent on the PC concentration. These results suggest that TF2A interacts with PC and aggregates in a specific manner different from catechins and other TFs. 相似文献
822.
Masaru Murakami Mitsuyuki Shirai Ryo Ooishi Asako Tsuburaya Kumiko Asai Osamu Hashimoto Kenji Ogawa Yoshii Nishino Masayuki Funaba 《Biochemical genetics》2013,51(3-4):202-210
The tissue distribution of activin receptor-like kinase 7 (Alk7) expression, the signaling ability of Alk7 variants, and Alk7 expression in response to β3-adrenergic receptor activation were examined. Expression levels of Alk7 varied greatly among tissues but were highest in white adipose tissue and brown adipose tissue. In addition to full-length Alk7 (Alk7-v1), Alk7-v3, an Alk7 variant, was expressed in adipose tissues, brain, and ovary. Nodal transmits signals via Alk7 in cooperation with its coreceptor, Cripto. Evaluation of the ability of Alk7 variants to confer Nodal signaling using luciferase-based reporter assays showed that Alk7-v3 does not transmit Nodal-Cripto-mediated signals. Expression of Alk7 was down-regulated in brown but not in white adipose tissue treated with CL316,243, a β3-adrenergic receptor agonist. These results suggest involvement of Alk7 in modulation of metabolism in the adipose tissues in response to β3-adrenergic receptor activation. 相似文献
823.
Takeshi Sassa Akihiro Takahama Tamotsu Shindo 《Bioscience, biotechnology, and biochemistry》2013,77(9):1729-1734
The stereostructure of cotylenol has been assigned as I on the basis of degradative and spectroscopic evidence. Cotylenol is a novel diterpene with ophiobolane skeleton. 相似文献
824.
Summary For analysing spatial distribution of maternal proteins in an amphibian egg, monoclonal antibodies specific to certain regions were raised. One monoclonal antibody was found (MoAB Xa5B6) which reacted specifically with the animal hemisphere of the mature Xenopus laevis egg. The maternal protein that reacted with the MoAb Xa5B6 was shown to be distributed asymmetrically along the dorso-ventral axis in the upper region of the equatorial zone of the fertilized egg. At late blastula stage, the antigen protein could be observed clearly in both the marginal zone and animal cap. It was localized predominantly in mesodermal and ectodermal cells of late neurula embryos. The Xa5B6 antigen accumulated during oogenesis. The distribution pattern of maternal protein was remarkably different in the developmental stages of the oocyte. The pattern in the mature oocyte was completely different from that of the immature egg in which the antigen was located in the radial striations of the oocyte cytoplasm. After maturation, the distribution pattern changed drastically to an animal-vegetal polarization and the striation labellings were no longer observed. By Western blot examination, it was confirmed that the amounts of antigen protein were constant during early embryogenesis and the mesoectoderm contained a greater amount of antigens than the endoderm at late blastula. The antibody detected two bands of approximately 70 × 103 and 30 × 103 Mr by Western blot analysis. The latter molecule may possibly be a degrading moiety of the former. The results were discussed in relation to establishment of animal-vegetal (A/V) and dorso-ventral (D/V) polarization at the molecular level.
Offprint requests to: A.S. Suzuki 相似文献
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826.
Yoshinori Toyoshima Kozo Akabori Akiko Imaoka Haruto Nakayama Nozomu Ohkouchi Asako Kawamori 《FEBS letters》1984,176(2):346-350
Extraction of PS II particles with 1 M CaCl2 caused complete disappearance of the light-induced signal of the possible Kok S2 state of the water-splitting complex and total loss of the O2, evolving activity, concomitant with perfect removal of the 17-, 23- and 34-kDa proteins from the particles. The recovery of the multiline signal in the CaCl2-treated PS II was performed by reinserting the 34-kDa protein, when CI? was present in the solution for the EPR measurement. However, in the absence of Cl?, besides the 34-kDa protein, the 17- and 23-kDa proteins were required for the recovery of the signal. These results are compared with the results on the recovery of the O2, evolution in the reconstituted PS II to examine the role of these three proteins on the water splitting. 相似文献
827.
828.
Samy Carbonnel Salar Torabi Maximilian Griesmann Elias Bleek Yuhong Tang Stefan Buchka Veronica Basso Mitsuru Shindo Franois-Didier Boyer Trevor L. Wang Michael Udvardi Mark T. Waters Caroline Gutjahr 《PLoS genetics》2020,16(12)
Karrikins (KARs), smoke-derived butenolides, are perceived by the α/β-fold hydrolase KARRIKIN INSENSITIVE2 (KAI2) and thought to mimic endogenous, yet elusive plant hormones tentatively called KAI2-ligands (KLs). The sensitivity to different karrikin types as well as the number of KAI2 paralogs varies among plant species, suggesting diversification and co-evolution of ligand-receptor relationships. We found that the genomes of legumes, comprising a number of important crops with protein-rich, nutritious seed, contain two or more KAI2 copies. We uncover sub-functionalization of the two KAI2 versions in the model legume Lotus japonicus and demonstrate differences in their ability to bind the synthetic ligand GR24ent-5DS in vitro and in genetic assays with Lotus japonicus and the heterologous Arabidopsis thaliana background. These differences can be explained by the exchange of a widely conserved phenylalanine in the binding pocket of KAI2a with a tryptophan in KAI2b, which arose independently in KAI2 proteins of several unrelated angiosperms. Furthermore, two polymorphic residues in the binding pocket are conserved across a number of legumes and may contribute to ligand binding preferences. The diversification of KAI2 binding pockets suggests the occurrence of several different KLs acting in non-fire following plants, or an escape from possible antagonistic exogenous molecules. Unexpectedly, L. japonicus responds to diverse synthetic KAI2-ligands in an organ-specific manner. Hypocotyl growth responds to KAR1, KAR2 and rac-GR24, while root system development responds only to KAR1. This differential responsiveness cannot be explained by receptor-ligand preferences alone, because LjKAI2a is sufficient for karrikin responses in the hypocotyl, while LjKAI2a and LjKAI2b operate redundantly in roots. Instead, it likely reflects differences between plant organs in their ability to transport or metabolise the synthetic KLs. Our findings provide new insights into the evolution and diversity of butenolide ligand-receptor relationships, and open novel research avenues into their ecological significance and the mechanisms controlling developmental responses to divergent KLs. 相似文献
829.
830.