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61.
Tatsuki Kikegawa Takuya Yamaguchi Ryohei Nambu Kenji Etchuya Masami Ikeda 《Bioscience, biotechnology, and biochemistry》2018,82(10):1708-1714
Despite studies of the mechanism underlying the intracellular localization of membrane proteins, the specific mechanisms by which each membrane protein localizes to the endoplasmic reticulum, Golgi apparatus, and plasma membrane in the secretory pathway are unclear. In this study, a discriminant analysis of endoplasmic reticulum, Golgi apparatus and plasma membrane-localized type II membrane proteins was performed using a position-specific scoring matrix derived from the amino acid propensity of the sequences around signal-anchors. The possibility that the sequence around the signal-anchor is a factor for identifying each localization group was evaluated. The discrimination accuracy between the Golgi apparatus and plasma membrane-localized type II membrane proteins was as high as 90%, indicating that, in addition to other factors, the sequence around signal-anchor is an essential component of the selection mechanism for the Golgi and plasma membrane localization. These results may improve the use of membrane proteins for drug delivery and therapeutic applications. 相似文献
62.
Masato Nikaido Kuniko Kawai Yin Cao Masashi Harada Satoru Tomita Norihiro Okada Masami Hasegawa 《Journal of molecular evolution》2001,53(4-5):508-516
The complete mitochondrial genomes of two microbats, the horseshoe bat Rhinolophus pumilus, and the Japanese pipistrelle Pipistrellus abramus, and that of an insectivore, the long-clawed shrew Sorex unguiculatus, were sequenced and analyzed phylogenetically by a maximum likelihood method in an effort to enhance our understanding of
mammalian evolution. Our analysis suggested that (1) a sister relationship exists between moles and shrews, which form an
eulipotyphlan clade; (2) chiropterans have a sister-relationship with eulipotyphlans; and (3) the Eulipotyphla/Chiroptera
clade is closely related to fereuungulates (Cetartiodactyla, Perissodactyla and Carnivora). Divergence times on the mammalian
tree were estimated from consideration of a relaxed molecular clock, the amino acid sequences of 12 concatenated mitochondrial
proteins and multiple reference criteria. Moles and shrews were estimated to have diverged approximately 48 MyrBP, and bats
and eulipotyphlans to have diverged 68 MyrBP. Recent phylogenetic controversy over the polyphyly of microbats, the monophyly
of rodents, and the position of hedgehogs is also examined.
Received: 21 December 2000 / Accepted: 16 February 2001 相似文献
63.
To understand how baidzharakhs (relic mounds enclosing polygonal ice blocks in permafrost) affect the zonal distribution of
vegetation, vegetation was measured in 145 plots of area 50 cm × 50 cm on a coastal terrace facing the Arctic Ocean in northern
Siberia. Cluster analysis classified five community types that were zonally distributed along the coastline. α-diversities
(species richness and diversity) were not different among vegetation types except for vegetation close to the coastline. On
and around baidzharakhs, burrows created by lemmings were frequently observed, and plant cover was low, suggesting that baidzharakhs
support habitats for rodents. Disturbances by rodent habits caused plant cover to decline but did not change α-diversity.
Two vegetation types that developed only on baidzharakhs were found at intermediate distances between the seacoast and inland
areas. Because these two vegetation types are azonally distributed, β- and γ-diversities were increased by permafrost-derived
topography, i.e., baidzharakh, and/or disturbance by rodents of which suitable nesting habitat is provided by baidzharakh. 相似文献
64.
Kunio Takeda Kyoko Ogawa Masami Ohara Satoshi Hamada Yoshiko Moriyama 《The protein journal》1995,14(8):679-684
Four disulfide bridges of bovineα-lactalbumin (α-lact) were selectively reduced to obtain its derivatives with three, two, and zero disulfide bridges (designated as 3SS, 2SS, and OSSα-lact, respectively). The original helicity was almost maintained in 3SSα-lact missing only the Cys6-Cysl20 bridge. Upon the reduction of both Cys28-Cys111 and Cys6-Cys120 bridges, various changes occurred in the protein. In particular, the maximum fluorescence of 1-anilinonaphthalene-8-sulfonic acid was observed in this stage. Upon the reduction of all disulfide bridges, the hydrophobic box of the protein, formed by Trp60, Ile95, Tyr103, and Trp104, was disrupted and an internal helical structure was destroyed. The conformation of each derivative was examined mainly in a solution of sodium dodecyl sulfate. In the surfactant solution, the helicity increased from 33% to 37% in 3SSα-lact, from 26% to 31% in 2SSα-lact, and from 18% to 37% in OSSα-lact, as against from 34% to 44% in intactα-lact. On the other hand, the tryptophan fluorescence of each derivative was affected in very low surfactant concentrations, suggesting that the tertiary structure considerably changed prior to the secondary structural change in the surfactant solution. 相似文献
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68.
Yamamoto S Matsunaga N Hitaka T Yamada M Hara T Miyazaki J Santou T Kusaka M Yamaoka M Kanzaki N Furuya S Tasaka A Hamamura K Ito M 《Bioorganic & medicinal chemistry》2012,20(1):422-434
A series of 4-phenylpyrrole derivatives D were designed, synthesized, and evaluated for their potential as novel orally available androgen receptor antagonists therapeutically effective against castration-resistant prostate cancers. 4-Phenylpyrrole compound 1 exhibited androgen receptor (AR) antagonistic activity against T877A and W741C mutant-type ARs as well as wild-type AR. An arylmethyl group incorporated into compound 1 contributed to enhancement of antagonistic activity. Compound 4n, 1-{[6-chloro-5-(hydroxymethyl)pyridin-3-yl]methyl}-4-(4-cyanophenyl)-2,5-dimethyl-1H-pyrrole-3-carbonitrile exhibited inhibitory effects on tumor cell growth against the bicalutamide-resistant LNCaP-cxD2 cell line as well as the androgen receptor-dependent JDCaP cell line in a mouse xenograft model. These results demonstrate that this series of pyrrole compounds are novel androgen receptor antagonists with efficacy against prostate cancer cells, including castration-resistant prostate cancers such as bicalutamide-resistant prostate cancer. 相似文献
69.
Onodera H Kaneko M Takahashi Y Uochi Y Funahashi J Nakashima T Soga S Suzuki M Ikeda S Yamashita Y Rahayu ES Kanda Y Ichimura M 《Bioorganic & medicinal chemistry letters》2008,18(5):1588-1591
Hsp90 is an attractive chemotherapeutic target because it is essential to maturation of multiple oncogenes. We describe the conformational significance of EH21A1-A4, phenolic derivatives of geldanamycin isolated from Streptomyces sp. Their native free structures are similar to the active form of geldanamycin bound to Hsp90 protein. Their conformational character is a probable reason for their high-affinity binding. Lack of toxic benzoquinone in EH21A1-A4 also adds to their potential as lead compounds for anti-tumor drugs. 相似文献
70.