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141.
142.
Plancitoxin I, the major lethal factor from the spines of crown-of-thorns starfish Acanthaster planci, is a 37 kDa protein composed of two different subunits, and it has potent hepatotoxicity. It is homologous with mammalian
deoxyribonuclease II (DNase II) and exhibits DNase activity responsible for the hepatotoxicity. To obtain information on the
structure–activity relationship of plancitoxin I, various mutants were expressed in Chinese hamster ovary cells and examined
for DNase activity. The results with deletion mutants revealed the requirement of the signal peptide for the expression of
intact plancitoxin I and the inability of each subunit to hydrolyze DNA. Mutation at the N-glycosylation site (Asn-274) did not reduce DNase activity, supporting the absence of carbohydrate moieties in the molecule.
The mutant H303A exhibited no DNase activity, suggesting the importance of His-303 for the enzymatic activity. No DNase activity
was detected in C29A, C169A, C318A and C337A, indicating that four Cys residues are critical to the enzymatic activity. However,
DNase activity was completely maintained in C263A and somewhat reduced in C277A and C357A. Based on the results with the Cys-specific
mutants, plancitoxin I was assumed to contain three disulfide bridges (29–169, 277–357 and 318–337) and one free Cys-263. 相似文献
143.
Kazuo Yagi Kazuhiko Akimoto Norihiko Mimori Toshiro Miyake Masaki Kudo Kazutaka Arai Shigeru Ishii 《Pest management science》2000,56(1):65-73
A series of novel 3‐(2,4,6‐trisubstituted phenyl)uracil derivatives has been synthesised and assayed for insecticidal/acaricidal activity. The assay indicated certain requirements for optimal insecticidal activity, which can be summarised as follows: (a) the substituents on the phenyl ring should possess hydrophobicity and electron‐withdrawing properties, and the sum of their volumes determines the level of activity; (b) the substituent at the 6‐position on the uracil ring should also possess electron‐withdrawing properties and hydrophobicity, together with the correct volume; (c) the 1‐position on the uracil ring should be unsubstituted for activity against Nephotettix cincticeps and Epilachna vigintioctopunctata, but substituents with length C3 to C4 may be optimal for activity against Tetranychus urticae; (d) certain substituents at the 5‐position of the uracil ring give activity against E vigintioctopunctata and T urticae, but not against N cincticeps; (e) a thiocarbonyl group at the 2‐position of the uracil ring is less effective than a carbonyl group. Of the compounds assayed, 3‐(2,6‐dichloro‐4‐trifluoromethylphenyl)‐6‐trifluoromethyluracil showed high activity against all the species assayed. © 2000 Society of Chemical Industry 相似文献
144.
Tomoyoshi Yoshinaga Nobuyuki Tsutsumi Kathryn Ann Hall Kazuo Ogawa 《Fisheries Science》2009,75(5):1167-1176
In the mid-1990s, Neoheterobothrium hirame suddenly appeared as a new species in olive flounder Paralichthys olivaceus in Japanese coastal waters. Anemia caused by the parasite has prevailed in wild and cultured populations of olive flounder since that time. In this study, to clarify the origin of N. hirame, two Neoheterobothrium species, namely unidentified Neoheterobothrium species (tentatively abbreviated as Neoheterobothrium sp. PL) and N. affine, were collected from Paralichthys lethostigma and Paralichthys dentatus, respectively, off the east coast of North America and compared with N. hirame collected in Japan. No substantial differences were detected in the morphology and DNA sequences of ITS1-5.8S rRNA-ITS2 and mitochondrial cytochrome oxidase subunit I (mt COI) regions between N. hirame and Neoheterobothrium sp. PL. On the other hand, the congeneric N. affine was clearly distinguished from both N. hirame and Neoheterobothrium sp. PL in its longer isthmus and the DNA sequences in ITS1 and mt COI. The absence of differences between N. hirame and Neoheterobothrium sp. PL and the clear difference between both of these and N. affine indicate that N. hirame is conspecific with Neoheterobothrium sp. PL infecting P. lethostigma and that N. hirame was recently introduced from North America to Japan. 相似文献
145.
Xiaojie Lu Junjie He Yanhua Wu Na Du Xiaofan Li Jianhua Ju Zhangli Hu Kazuo Umezawa Liyan Wang 《Marine drugs》2020,18(12)
In the present study, four new compounds including a pair of 2-benzoyl tetrahydrofuran enantiomers, namely, (−)-1S-myrothecol (1a) and (+)-1R-myrothecol (1b), a methoxy-myrothecol racemate (2), and an azaphilone derivative, myrothin (3), were isolated along with four known compounds (4–7) from cultures of the deep-sea fungus Myrothecium sp. BZO-L062. Enantiomeric compounds 1a and 1b were separated through normal-phase chiral high-performance liquid chromatography. The absolute configurations of 1a, 1b, and 3 were assigned by ECD spectra. Among them, the new compound 1a and its enantiomer 1b exhibited anti-inflammatory activity, inhibited nitric oxide formation in lipopolysaccharide-treated RAW264.7 cells, and exhibited antioxidant activity in the 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) and oxygen radical absorbance capacity assays. 相似文献
146.
Prevalence and Species Identity of Trypanorhyncha in Cultured and Wild Amberjack,Seriola spp. in Hawaii – Implications for Aquaculture 下载免费PDF全文
Clyde S. Tamaru RuthEllen C. Klinger‐Bowen Kazuo Ogawa Takashi Iwaki Akira Kurashima Naoki Itoh 《Journal of the World Aquaculture Society》2016,47(1):42-50
The advent of molecular technologies allow for identification of organisms that were previously challenging or not possible. Conventional polymerase chain reaction analyses of a segment of the small subunit ribosomal RNA gene from trypanorhynch plerocerci obtained from cultured and wild caught amberjacks, Seriola dumerili, and Seriola rivoliana of the family Carangidae from Hawai‘i and Japan were found to be 100% identical, indicating that the cestodes from Japan and Hawai‘i are the same species, Protogrillotia zerbiae. The prevalence of the trypanorhynch plerocerci found in the musculature of Hawai‘i wild‐caught S. dumerili and S. rivoliana was 86.9 and 72.7%, respectively. In stark contrast, no trypanorhynch plerocerci have been detected in S. rivoliana cultured in Hawai‘i and they are only rarely seen in S. dumerili cultured in Japan. Trypanorhynch plerocerci are part of a complex life cycle that involves the transmission in at least two intermediate hosts before finally residing in a host shark species. The results of this study indicate that artificial propagation of the amberjacks using manipulated diets has most likely disrupted the life cycle of this tapeworm, thus reducing the prevalence of this parasite in farmed amberjacks and enhancing the marketability of cultured amberjack. 相似文献
147.
Wagner Rodrigo de Souza Nelson Geraldo de Oliveira Felipe Vinecky Ana Paula Ribeiro Marcos Fernando Basso Raphael Augusto das Chagas Noqueli Casari Brbara Andrade Dias Brito da Cunha Karoline Estefani Duarte Thaís Ribeiro Santiago Polyana Kelly Martins Carlos Eduardo Aucique‐Perez Sílvio Carlos Cristofoletti Júnior Alexandre Lima Nepomuceno Carlos Antnio Ferreira de Sousa Adilson Kenji Kobayashi Kazuo Nakashima Kazuko Yamaguchi‐Shinozaki Hugo Bruno Correa Molinari 《Journal of Agronomy and Crop Science》2019,205(6):545-553
148.
149.
Kazuo Watanabe Matilde Orrillo Masaru Iwanaga Rodomiro Ortiz Rosanna Freyre Simon Perez 《American Journal of Potato Research》1994,71(9):599-604
Diploid cultivated species, haploids derived from tetraploid cultivars, and their wildSolanum relatives were used to generate various diploid potato genetic stocks. These stocks have significant value in potato breeding because: 1) genetic diversity in the potato population can be kept variable with the diploid germplasm which confers genetic variation from wild and cultivated species; 2) crossability of this diploid germplasm is facilitated by the function of 2n gametes; and 3) high levels of pest resistances originating from the process of introgression of the wild and cultivated genetic resources can be used to improve the tetraploid cultivated potato genepool. 相似文献
150.
Yoshiyuki Miyazawa Chanhsom Manythong Shinji Fukuda Kazuo Ogata 《Agroforestry Systems》2014,88(5):907-919
In rural areas of northern Laos, a commercially valuable pioneer tree species, paper mulberry (Broussonetia papyrifera L. Vent.) has been recommended for intercropping under plantations of commercial trees. However, less is understood about the growth of this pioneer tree species in the understorey and the mechanism underlying the shade intolerance. We measured growth characteristics for seedlings of paper mulberry under four light intensities. We compared the relative growth rates in aboveground biomass and standing leaf area (RGRmass and RGRleaf), light-capture efficiency, and seeding-level mass-based daily photosynthetic rates (A mass) with those of field-grown seedlings of eight shade-tolerant species to identify factors potentially responsible for shade-intolerance. Most growth traits of the paper mulberry seedlings did not differ consistently from those of the shade tolerant species. The ecophysiological–architectural model software showed higher A mass and RGRmass capacity in paper mulberry than in shade-tolerant species. Despite their higher RGRmass, paper mulberry seedlings had negative RGRleaf under shaded conditions due to short leaf lifespan. The linear RGRmass–RGRleaf relationship for paper mulberry had a high RGRmass intercept, indicating that a high RGRmass was required to provide positive RGRleaf. Progressive decreases in standing leaf area with time, and possibly photosynthesis, appear to be responsible for the shade-intolerance of paper mulberry. Although intercropping of paper mulberry has been suggested in the species’ native region, understorey cultivation of paper mulberry would only be possible with relatively open canopies. 相似文献