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21.
Yasuo Kishimoto Hiroshi Akanuma Inderjit Singh 《Molecular and cellular biochemistry》1979,28(1-3):93-105
Summary -Hydroxylation is an enzymatic reaction by which long-chain fatty acids are converted to their -hydroxy derivatives. This reaction, in animals, can be detected only in developing brain and is the rate-determining step in the synthesis of hydroxycerebroside, which is an indispensable and abundant myelin lipid. In addition to a particulate fraction from brain, two cytoplasmic factors, one heat-stable and the other heat-labile, are required for -hydroxylation. During the past eight years we have been investigating -hydroxylation. Our progress is summarized and discussed here. 相似文献
22.
The rate of lecithin:cholesterole acyltransferase reaction was measured in a cholesterol-containing single bilayer lecithin vesicle system. ApolipoproteinA-I (apoA-I) activated the enzyme by itself; the other components of apolipoproteins of high density lipoproteins (HDL) (rho = 1.08--1.2 g/cm3), or rabbit serum gamma globulin inhibited the reaction. The reaction which was activated by pure apoA-I was strongly inhibited by anti-apoA-I antibody. Quantitative analysis of the results showed that the lecithin:cholesterol acyltransferase reaction was activated by the binding of apoA-I to the surface of lipid substrates. The rate of the lecithin:cholesterol acyltransferase-catalyzed reaction was strictly proportional to the surface density of apoA-I. The inhibition was due to the decrease of the amount of apoA-I on the lipid surface, either through competitive exclusion by apoA-II or by other proteins, or through specific extraction with antibody. The presence of components of apoHDL, other than apoA-I, prevented the inhibitory action of anti-apoA-I antibody. 相似文献
23.
D-manno-3-Heptulose (5) was synthesized by dimethyl sulfoxide-phosphorus pentaoxide oxidation of 1,2:3,4:6,7-tri-O-isopropylidene-D-glycero-D-manno-heptitol (3, prepared from volemitol), followed by hydrolysis. D-ido-3-Heptulose (8) was synthesized similarly by oxidation of 1,2:4,5:6,7-tri-O-isopropylidene-D-glycero-l-galacto-heptitol (7, prepared from D-glycero-l-galacto-heptitol, 6). Another tri-O-isopropylidene derivative (11), having a free primary hydroxyl group, was produced in larger amount than 7, and 11 yielded D-glycero-l-galacto-heptose (14). Compound 8 was also synthesized by way of 1,2:4,5.6,7-tri-O-isopropylidene-D-glycero-l-gulo-heptitol (15). The production of 15 from D-glycero-l-gulo-heptitol (13) was accompanied by a larger amount of 2,3:4,5:6,7-tri-O-isopropylidene-D-glycero-D-ido-heptitol (17) which, upon oxidation followed by hydrolysis, yielded D-glycero-D-ido-heptose (18). One of the two tri-O-isopropylidene derivatives obtained by acetonation of perseitol, 2,3:4,5:6,7-tri-O-isopropylidene-D-glycero-D-galacto-heptitol (19), yielded D-glycero-D-galacto-heptose (20). 相似文献
24.
25.
Kyoko Saio Emiko Koyama Tokuji Watanabe 《Bioscience, biotechnology, and biochemistry》2013,77(10):1195-1200
This paper constitutes the first report in a research series undertaken in order to clarify the interactive relationships among soybean meal protein, calcium and phytic acid in solution and in precipitate.Data presented are mainly concerned with solubility characteristics of soybean meal proteins as a function of pH. The results support the suggestion as follows; phosphorus and calcium give the remarkable effects on solubility characteristics of protein, the complex containing protein, calcium and phosphorus is formed above isoelectric point of protein and the combinations are labile above at pH 8, especially by heating. 相似文献
26.
Suzuki Setsuko Kyoko Sugai Ichiro Tamaki Koji Takayama Hidetoshi Kato Hiroshi Yoshimaru 《Molecular ecology》2020,29(6):1050-1068
Pandanus boninensis, endemic to the Ogasawara Islands, Japan, is distributed on both the older Bonin and younger Volcano Islands. In this study, we conducted population genetic analyses of P. boninensis on these islands to examine the population diversity and structure across old and young islands, to assess potential differences in population demography with island age, and to collect any evidence of migration between old and young islands. We found that the genetic diversity of expressed sequence tag (EST)–based microsatellite (SSR) markers, the nucleotide diversity of nuclear DNA sequences, and the haplotype diversity of chloroplast DNA on young islands were lower than those on old islands. Clustering analyses of EST‐SSR indicated that populations on old islands were strongly diverged from those on young islands. Approximate Bayesian computation analysis of EST‐SSR suggested that population expansion occurred on old islands while population reduction occurred on young islands. We also found evidence of migration among old islands (mostly from south to north), while it appears that there have been very few migration events between old and young islands. These differences could be due to the fact that young islands tend to be geographically isolated and support smaller populations that began a shorter time ago from limited founders. The P. boninensis populations on the Volcano Islands are interesting from an evolutionary perspective as they constitute a classic example of the early stages of progressive colonization on oceanic islands with small effective population sizes and low genetic diversity. 相似文献
27.
Aida Rieko Hagiwara Keitaro Okano Kazunori Nakata Kyoko Obata Yuho Yamashita Takahiro Yoshida Kaoru Hagiwara Hiromi 《Molecular biology reports》2021,48(3):2291-2297
Molecular Biology Reports - Apigenin is a flavonoid with antioxidant and anticancer effects. It has been reported that apigenin inhibits proliferation, migration, and invasion and induces apoptosis... 相似文献
28.
Miyako Kondoh Noritaka Ohga Kosuke Akiyama Yasuhiro Hida Nako Maishi Alam Mohammad Towfik Nobuo Inoue Masanobu Shindoh Kyoko Hida 《PloS one》2013,8(11)
There is much evidence that hypoxia in the tumor microenvironment enhances tumor progression. In an earlier study, we reported abnormal phenotypes of tumor-associated endothelial cells such as those resistant to chemotherapy and chromosomal instability. Here we investigated the role of hypoxia in the acquisition of chromosomal abnormalities in endothelial cells. Tumor-associated endothelial cells isolated from human tumor xenografts showed chromosomal abnormalities, >30% of which were aneuploidy. Aneuploidy of the tumor-associated endothelial cells was also shown by simultaneous in-situ hybridization for chromosome 17 and by immunohistochemistry with anti-CD31 antibody for endothelial staining. The aneuploid cells were surrounded by a pimonidazole-positive area, indicating hypoxia. Human microvascular endothelial cells expressed hypoxia-inducible factor 1 and vascular endothelial growth factor A in response to either hypoxia or hypoxia-reoxygenation, and in these conditions, they acquired aneuploidy in 7 days. Induction of aneuploidy was inhibited by either inhibition of vascular endothelial growth factor signaling with vascular endothelial growth factor receptor 2 inhibitor or by inhibition of reactive oxygen species by N-acetyl-L-cysteine. These results indicate that hypoxia induces chromosomal abnormalities in endothelial cells through the induction of reactive oxygen species and excess signaling of vascular endothelial growth factor in the tumor microenvironment. 相似文献
29.
Braarudosphaera bigelowii (Prymnesiophyceae) is a coastal coccolithophore with a long fossil record, extending back to the late Cretaceous (ca. 100 Ma). A recent study revealed close phylogenetic relationships between B. bigelowii, Chrysochromulina parkeae (Prymnesiophyceae), and a prymnesiophyte that forms a symbiotic association with the nitrogen-fixing cyanobacterium UCYN-A. In order to further examine these relationships, we conducted transmission electron microscopic and molecular phylogenetic studies of B. bigelowii. TEM studies showed that, in addition to organelles, such as the nucleus, chloroplasts and mitochondria, B. bigelowii contains one or two spheroid bodies with internal lamellae. In the 18S rDNA tree of the Prymnesiophyceae, C. parkeae fell within the B. bigelowii clade, and was close to B. bigelowii Genotype III (99.89% similarity). Plastid 16S rDNA sequences obtained from B. bigelowii were close to the unidentified sequences from the oligotrophic SE Pacific Ocean (e.g. ) (99.86% similarity). Bacterial16S rDNA sequences obtained from B. bigelowii were identical to the UCYN-A sequence HM133411 from Arabian Sea, and fell in the UCYN-A clade. From these results, we suggest that; 1) C. parkeae is the alternate life cycle stage of B. bigelowii sensu stricto or that of a sibling species of B. bigelowii, and 2) the spheroid body of B. bigelowii originated from endosymbiosis of the nitrogen-fixing cyanobacterium UCYN-A. AY621693相似文献
30.
Shutaro Ishimura Masato Furuhashi Yuki Watanabe Kyoko Hoshina Takahiro Fuseya Tomohiro Mita Yusuke Okazaki Masayuki Koyama Marenao Tanaka Hiroshi Akasaka Hirofumi Ohnishi Hideaki Yoshida Shigeyuki Saitoh Tetsuji Miura 《PloS one》2013,8(11)