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71.
The blend miscibility of cellulose propionate (CP) with poly(N-vinyl pyrrolidone-co-methyl methacrylate) (P(VP-co-MMA)) was investigated. The degree of substitution (DS) of CP used ranged from 1.6 to >2.9, and samples for the vinyl polymer component were prepared in a full range of VP:MMA compositions. Through DSC analysis and solid-state 13C NMR and FT-IR measurements, we revealed that CPs of DS < 2.7 were miscible with P(VP-co-MMA)s of VP ≥ ∼10 mol% on a scale within a few nanometers, in virtue of hydrogen-bonding interactions between CP-hydroxyls and VP-carbonyls. When the DS of CP exceeded 2.7, the miscibility was restricted to the polymer pairs using P(VP-co-MMA)s of VP = ca. 10–40 mol%; the scale of mixing in the blends concerned was somewhat larger (ca. 5–20 nm), however. The appearance of such a “miscibility window” was interpretable as an effect of intramolecular repulsion in the copolymer component. Results of DMA and birefringence measurements indicated that the miscible blending of CP with the vinyl polymer invited synergistic improvements in thermomechanical and optical properties of the respective constituent polymers. Additionally, it was found that the VP:MMA composition range corresponding to the miscibility window was expanded by modification of the CP component into cellulose acetate propionate. 相似文献
72.
Jun-ichi Sakabe Mami Yamamoto Satoshi Hirakawa Akira Motoyama Isao Ohta Kazuki Tatsuno Taisuke Ito Kenji Kabashima Toshihiko Hibino Yoshiki Tokura 《The Journal of biological chemistry》2013,288(24):17179-17189
Filaggrin protein is synthesized in the stratum granulosum of the skin and contributes to the formation of the human skin barrier. Profilaggrin is cleaved by proteolytic enzymes and converted to functional filaggrin, but its processing mechanism remains not fully elucidated. Kallikrein-related peptidase 5 (KLK5) is a major serine protease found in the skin, which is secreted from lamellar granules following its expression in the stratum granulosum and activated in the extracellular space of the stratum corneum. Here, we searched for profilaggrin-processing protease(s) by partial purification of epidermal extracts and found KLK5 as a possible candidate. We used high performance liquid chromatography coupled with electrospray tandem mass spectrometry to show that KLK5 cleaves profilaggrin. Furthermore, based on a proximity ligation assay, immunohistochemistry, and immunoelectron microscopy analysis, we reveal that KLK5 and profilaggrin co-localize in the stratum granulosum in human epidermis. KLK5 knockdown in normal cultured human epidermal keratinocytes resulted in higher levels of profilaggrin, indicating that KLK5 potentially functions in profilaggrin cleavage. 相似文献
73.
Tomoya Suzuki Takashi Tanizawa Kazuki Sekiné Junko Kunimi Koji Tojo 《Biological journal of the Linnean Society. Linnean Society of London》2013,110(3):615-643
The East Asian giant water bug species Appasus japonicus Vuillefroy and Appasus major Esaki are aquatic hemipteran insects whose ranges overlap, particularly in the Japanese Archipelago and on the Korean Peninsula. In rare cases, the two species co‐occur. Furthermore, they are very similar ecologically and also morphologically, making their identification extremely difficult, and the possibility of hybridization has also been suggested. In the present study, we re‐examined their taxonomic validity, and the characteristics useful for identifying them. To re‐examine the morphological traits useful for distinguishing these two species, 222 specimens of A. japonicus collected from Japan, Korea, and China, and 132 specimens of A. major from Japan and Korea, were examined. We also performed molecular phylogenetic analyses based on the mitochondrial DNA 16S rRNA and cytochrome oxidase subunit I (COI) regions and the nuclear DNA Histone 3 region. Although the two species are very similar ecologically and also morphologically, they showed significant genetic differentiation. Thus, there is likely some form of reproductive isolation acting between them. Major morphological characteristics overlap extensively between A. japonicus and A. major, and no particular trait was identified as being effective for differentiating these species. All the morphological characteristics examined overlapped between A. japonicus and A. major. However, a principal component analysis based on all of the morphological characteristics revealed that, despite the overlap between these species, it was possible to morphologically distinguish them. Therefore, a more accurate identification becomes possible using multiple characteristics rather than a single characteristic. The male genital paralobes, evaluated as the most useful morphological characteristic, was effective with 100% probability for the Japanese Appasus species. However, for the Asian (i.e. Korean) specimens, this characteristic was not useful. On the other hand, the results of molecular phylogenetic analyses based on the mitochondrial DNA 16S rRNA and COI regions and the nuclear DNA Histone 3 region clearly showed significant genetic differentiation between the two species. Notably, the results for the mitochondrial COI region strongly supported the independence of each monophyletic group (i.e. validity of each species). Therefore, DNA barcoding based on the mitochondrial DNA COI region is also considered useful for the identification of A. japonicus and A. major. © 2013 The Linnean Society of London, Biological Journal of the Linnean Society, 2013, 110 , 615–643. 相似文献
74.
Kazuyuki Nakamura Hirofumi Kodera Tenpei Akita Masaaki Shiina Mitsuhiro Kato Hideki Hoshino Hiroshi Terashima Hitoshi Osaka Shinichi Nakamura Jun Tohyama Tatsuro Kumada Tomonori Furukawa Satomi Iwata Takashi Shiihara Masaya Kubota Satoko Miyatake Eriko Koshimizu Kiyomi Nishiyama Mitsuko Nakashima Yoshinori Tsurusaki Noriko Miyake Kiyoshi Hayasaka Kazuhiro Ogata Atsuo Fukuda Naomichi Matsumoto Hirotomo Saitsu 《American journal of human genetics》2013
75.
Yuan Si Kazuki Inoue Katsuhide Igarashi Jun Kanno Yuuki Imai 《Biochemical and biophysical research communications》2013
Chondrocyte differentiation is controlled by various regulators, such as Sox9 and Runx2, but the process is complex. To further understand the precise underlying molecular mechanisms of chondrocyte differentiation, we aimed to identify a novel regulatory factor of chondrocyte differentiation using gene expression profiles of micromass-cultured chondrocytes at different differentiation stages. From the results of microarray analysis, the autoimmune regulator, Aire, was identified as a novel regulator. Aire stable knockdown cells, and primary cultured chondrocytes obtained from Aire−/− mice, showed reduced mRNA expression levels of chondrocyte-related genes. Over-expression of Aire induced the early stages of chondrocyte differentiation by facilitating expression of Bmp2. A ChIP assay revealed that Aire was recruited on an Airebinding site (T box) in the Bmp2 promoter region in the early stages of chondrocyte differentiation and histone methylation was modified. These results suggest that Aire can facilitate early chondrocyte differentiation by expression of Bmp2 through altering the histone modification status of the promoter region of Bmp2. 相似文献
76.
Keiji Saito Akira Nakao Tsuyoshi Shinozuka Kousei Shimada Satoshi Matsui Kiyoshi Oizumi Kazuki Yano Keiko Ohata Daisuke Nakai Yoko Nagai Satoru Naito 《Bioorganic & medicinal chemistry》2013,21(7):1628-1642
A cell-based assay was performed for the discovery of novel bone anabolic agents. Alkaline phosphatase (ALPase) activity of ST2 cells was utilized as an indicator of osteoblastic differentiation, and thienopyridine derivative 1 was identified as a hit compound. 3-Aminothieno[2,3-b]pyridine-2-carboxamide was confirmed to be a necessary core structure for the enhancement of ALPase activity, and then optimization of the C4-substituent on the thienopyridine ring was carried out. Introduction of cyclic amino groups to the C4-position of the thienopyridine ring improved the activity. Especially, N-phenyl-homopiperazine derivatives were found to be strong enhancers of ALPase among this new series. Furthermore, 3-amino-4-(4-phenyl-1,4-diazepan-1-yl)thieno[2,3-b]pyridine-2-carboxamide (15k) was orally administered to ovariectomized (OVX) rats over 6 weeks for evaluating the effects on areal bone mineral density (aBMD), and statistically significant improvements in aBMD were observed from the dosage of 10 mg/kg/day. 相似文献
77.
Masaya Shimada Kazuki Mochizuki Toshinao Goda 《The Journal of nutritional biochemistry》2013,24(3):606-612
Methylated histone H3 at lysine 4 (K4) is associated with euchromatin and is involved in the transactivation of genes. However, it is unknown whether histone methylation is involved with changes in gene expression induced by nutrients. In this study, we examined whether methylations of histone H3 at K4 on maltase-glucoamylase (Mgam), which is responsible for the digestion of starch in the small intestine, as well as Mgam expression were altered by feeding rats an indigestible starch (resistant starch, RS). The mRNA and protein levels and the activities of MGAM were reduced in rats fed an RS diet compared with those fed a regular starch diet. Furthermore, we found that decreases in di- and tri-methylation of histone H3 at K4, as well as reduced acetylation of histones H3 and H4 on the Mgam gene were associated with a reduction of Mgam gene expression. These results suggest that the reductions of jejunal MGAM levels and activities caused by the RS diet are regulated at the mRNA level through a decrease in methylation of histone H3 at K4 and reduced acetylation of histones H3 and H4 on the Mgam gene. 相似文献
78.
Tomohide Uno Kazuki Sakamoto Yuri Isoyama Susumu Hiragaki Yuichi Uno Kengo Kanamaru Hiroshi Yamagata Michihiro Takagi Akira Mizoguchi Makio Takeda 《Histochemistry and cell biology》2013,139(2):299-308
Rab proteins are small GTPases that play essential roles in vesicle transport. In this study, we examined the expression of Rab proteins and neuropeptide hormones in the brain of the silkworm, Bombyx mori. We produced antibodies against B. mori Rab1 and Rab14 in rabbits. Immunoblotting of samples of brain tissue from B. mori revealed a single band for each antibody. Rab1 and Rab14 immunohistochemical labeling in the brain of B. mori was restricted to neurons of the pars intercerebralis and dorsolateral protocerebrum. Rab1, Rab7 and Rab14 co-localized with bombyxin. Rab1 and Rab7 co-localized with eclosion hormone. Rab1 co-localized with prothoracicotropic hormone. These results suggest that Rab1, Rab7 and Rab14 may be involved in neuropeptide transport in the brain of B. mori. This is the first report on the specificity of Rab proteins for the secretion of different neuropeptides in insects. 相似文献
79.
Hitoshi Ashida Kazuki Kanazawa Masato Natake 《Bioscience, biotechnology, and biochemistry》2013,77(8):2007-2014
Linoleic acid, and its hydroperoxides and secondary autoxidation products were orally administered to rats (400 mg/rat). Their effects on hepatic lipid metabolism were examined. Linoleic acid reduced the activities of de novo synthesis of fatty acids and acetyl-CoA carboxylase. It decreased the CoASH level and caused the accumulation of long-chain acyl-CoA. Hydroperoxides changed the compositions of unsaturated fatty acids in the hepatic lipids and lowered the content of neutral lipids. Secondary products stimulated carnitine palmitoyltransferase and decreased the content of neutral lipids. They reduced the activities of de novo synthesis of fatty acids and acetyl-CoA carboxylase, and the levels of CoASH and acetyl-CoA. Thus, the effect of secondary products was apparently different from those of linoleic acid and its hydroperoxides. 相似文献
80.
An inulinase was highly purified from the culture broth of Penicillium purpurogenum by chromatographies on DEAE-Sepharose CL-6B, Toyopearl HW-65, and Bio-Gel P-100. The enzyme was homogeneous by disc electrophoretic analysis. The molecular weight was 6.4 × 104 by SDS-disc electrophoresis and gel filtration on Bio-Gel P-150. The isoelectric point was pH 3.6 by isoelectric focusing. The enzyme hydrolyzed inulin rapidly, but did not affect sucrose. By paper chromatography analysis, the major products from inulin were tri-, tetra-, penta-, and hexa-saccharides. The substrate specificity of the enzyme on hydrolyses of fructo-oligosaccharides[1F(1-β-d-fructofuranosyl)n sucrose (n = 1 to 6 and n (average of polymerization degree) = 8)] were examined. The Km values and relative maximum velocities for the hydrolyses of inulin and fructo-oligosaccharides (GFn, n = 2 to 7 and n = 9) were as follows: inulin, (DP = 35) 0.21 mM and 100; GF9, 0.24 mM and 86.5; GF7, 0.33 mM and 132; GF6, 0.85 mM and 71.2; GF5, 3.8 mM and 25.4; GF4, 2.8 mM and 28.8; GF3, (nystose) 16 mM and 0.8; GF2 (1-kestose), 8.4 mM and 0.2. The molecular activities for the hydrolyses of fructo-oligosaccharides (GFn, n = 2 to 6) were increased depending on the degree of polymerization of fructosyl residues, and were nearly constant if the polymerization degree was over seven. These results strongly suggested that the endo-type inulinase from Penicillium purpurogenum had a subsite structure consisting of at least seven subsites. 相似文献