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81.
Zhou M Morgner N Barrera NP Politis A Isaacson SC Matak-Vinković D Murata T Bernal RA Stock D Robinson CV 《Science (New York, N.Y.)》2011,334(6054):380-385
The ability of electrospray to propel large viruses into a mass spectrometer is established and is rationalized by analogy to the atmospheric transmission of the common cold. Much less clear is the fate of membrane-embedded molecular machines in the gas phase. Here we show that rotary adenosine triphosphatases (ATPases)/synthases from Thermus thermophilus and Enterococcus hirae can be maintained intact with membrane and soluble subunit interactions preserved in vacuum. Mass spectra reveal subunit stoichiometries and the identity of tightly bound lipids within the membrane rotors. Moreover, subcomplexes formed in solution and gas phases reveal the regulatory effects of nucleotide binding on both ATP hydrolysis and proton translocation. Consequently, we can link specific lipid and nucleotide binding with distinct regulatory roles. 相似文献
82.
The membrane rotor ring from the vacuolar-type (V-type) sodium ion-pumping adenosine triphosphatase (Na+-ATPase) from Enterococcus hirae consists of 10 NtpK subunits, which are homologs of the 16-kilodalton and 8-kilodalton proteolipids found in other V-ATPases and in F1Fo- or F-ATPases, respectively. Each NtpK subunit has four transmembrane alpha helices, with a sodium ion bound between helices 2 and 4 at a site buried deeply in the membrane that includes the essential residue glutamate-139. This site is probably connected to the membrane surface by two half-channels in subunit NtpI, against which the ring rotates. Symmetry mismatch between the rotor and catalytic domains appears to be an intrinsic feature of both V- and F-ATPases. 相似文献
83.
Shinpei Banno Hidenari Saito Hiroshi Sakai Toshihiko Urushibara Kentaro Ikeda Takeshi Kabe Isao Kemmochi Makoto Fujimura 《Journal of General Plant Pathology》2011,77(5):282-291
Verticillium longisporum and V. dahliae, causal agents of Verticillium wilt, are spreading through the cabbage fields of Gunma Prefecture. Using the V. longisporum-specific intron within the 18S rDNA and differences between ITS 5.8S rDNA sequences in Japanese isolates of V. longisporum and V. dahliae, we developed three quantitative nested real-time (QNRT) PCR assays. The QNRT-PCR quantification of V. longisporum or V. dahliae in cabbage field soil was consistent with the severity of Verticillium wilt disease in those fields. In field trials of resistant
cultivar YR Ranpo grown for three seasons in soil infested with the pathogen, disease severity and pathogen density in the
soil were significantly reduced in a field moderately contaminated by V. dahliae, but only slightly reduced in a highly contaminated field. These results suggest that continuous cultivation of a resistant
cultivar is an effective way to reduce the pathogen population. QNRT-PCR assays provide a powerful analytical tool to evaluate
the soil population dynamics of V. longisporum and V. dahliae for disease management. 相似文献
84.
Rapid oligotrophication by the operation of the ‘Bio-filter system’ has changed Doh-Hoh-Numa Bog from a moderate mesotrophic system to the oligotrophic end of such a system. However, the population growth rate of the bacterioplankton community was little affected, and continued to be controlled primarily by the DOC concentration even after the system operation. This DOC concentration was higher during the operation period, although environmental factors relevant to primary production were shifted to the direction of oligotrophication. The natural bacterioplankton community in the bog was shown to modify its physiological kinetics to maintain the growth rate at the optimal level, even when it was exposed to oligotrophication processes with the operation of the ‘Bio-filter system’. 相似文献
85.
Food-drug interaction between ferulic acid and nateglinide involving the fluorescein/H+ cotransport system 总被引:2,自引:0,他引:2
Itagaki S Kobayashi Y Otsuka Y Kubo S Kobayashi M Hirano T Iseki K 《Journal of agricultural and food chemistry》2005,53(7):2499-2502
In clinical, patients usually take many kinds of drugs at the same time. Thus, drug-drug interactions involving transporters can often directly affect the therapeutic safety and efficacy of many drugs. However, there have been few studies on food-drug interactions involving transporters. Dietary polyphenols have been widely assumed to be beneficial to human health. Polyphenols are commercially prepared and used as functional foods. We report here for the first time that ferulic acid, which is widely used as a functional food, affects the transport of clinical agents. It is important to be aware of the potential of food-drug interactions and to act in order to prevent undesirable and harmful clinical consequences. 相似文献
86.
Takeshi Izuta Taeko Yamaoka Tatsuro Nakaji Tetsushi Yonekura Masaaki Yokoyama Hideyuki Matsumura Sachie Ishida Kenichi Yazaki Ryo Funada Takayoshi Koike 《Water, air, and soil pollution》2001,130(1-4):1007-1012
Dry matter production, net photosynthetic rate, leaf nutrient status and trunk anatomical characteristics of Fagus crenata seedlings grown in brown forest soil acidified by adding H2SO4 solution were investigated. The soil acidification leaded to decreased (Ca+Mg+K)/Al molar ratio in the soil solution. Dry mass per plant of the seedlings grown in the soil treated with H+ at 120 mg·L?1 was significantly reduced compared with the control value at 0 mg·L?1. When net photosynthetic rate was reduced in the seedlings grown in the soil treated with H+ at 120 mg·L?1, the carboxylation efficiency and maximum net photosynthetic rate at saturated CO2-concentration were lower than the control values. The addition of H+ to the soil at 120 mg·L?1iinduced a reduction in the concentration of Ca in the leaf. By contrast, the concentration of Al in the leaf was increased with increasing the amount of H+ added to the soil. The annual ring formed in the seedlings grown in the soil treated with H+ at 120 mg·L?1 was significantly narrower than that at 0 (control), 10, 30, 60 or 90 mg·L?1. Based on the results obtained in the present study, we conclude that Fagus crenata is relatively sensitive to a reduction in the (Ca+Mg+K)/Al molar ratio of soil solution compared with Picea abies. 相似文献
87.
Masayuki HOJITO Kentaro HAYASHI Kentaro MURANO Akinori MORI 《Soil Science and Plant Nutrition》2006,52(2):253-253
(pp. 41–46)
Silicon availability in 36 commercial nursery bed soils was evaluated by four methods the phosphate buffer (pH 6.2, 40 mmol L−1 ), incubation, supernatant and acetate buffer (pH 4.0, 1 mol L−1 ) Methods. The influence of silicon availability in the nursery bed soils on the silicon uptake of rice Oryza sativa L. cv. Hitomebore seedlings and the effect of silicon fertilizer application were examined in a glass house in 2002.
The results revealed that the best correlation between silicon content in rice seedlings and available silicon in soils was obtained with the phosphate buffer-solution method ( r = 0.86). More precise evaluation of available silicon was achieved by grouping soils based on these phosphate absorption coefficients (PAC). The correlation coefficients between silicon content in rice seedlings and available silicon in soils were 0.92 and 0.72 for volcanic soils (PAC > 1500) and non volcanic soils (PAC < 1500), respectively.
We concluded that the phosphate buffer method is the most easily adjusted method for estimation of silicon availability in nursery bed soils, and silicon fertilizers should be applied when silicon availability in non-volcanic nursery bed soils goes below 200 mg kg−1 , whereas the level is less than 350 mg kg−1 in volcanic soils. 相似文献
Silicon availability in 36 commercial nursery bed soils was evaluated by four methods the phosphate buffer (pH 6.2, 40 mmol L
The results revealed that the best correlation between silicon content in rice seedlings and available silicon in soils was obtained with the phosphate buffer-solution method ( r = 0.86). More precise evaluation of available silicon was achieved by grouping soils based on these phosphate absorption coefficients (PAC). The correlation coefficients between silicon content in rice seedlings and available silicon in soils were 0.92 and 0.72 for volcanic soils (PAC > 1500) and non volcanic soils (PAC < 1500), respectively.
We concluded that the phosphate buffer method is the most easily adjusted method for estimation of silicon availability in nursery bed soils, and silicon fertilizers should be applied when silicon availability in non-volcanic nursery bed soils goes below 200 mg kg
88.
89.
ABSTRACT: The appropriate water velocity in artificial burrows for theJapanese crayfish species Cambaroides japonicus was studied.An experimental system of two artificial burrows (burrows A and B)of the same size was set in a large tank. The velocity of burrowA was 0 cm/s and that of burrow B was varied andset at 0 cm/s, 5 cm/s, 10 cm/s,20 cm/s and 30 cm/s. The selectionof these two burrows by C. japonicus was observed. No animalsselected burrow B significantly more than burrow A above 10 cm/s.At 20 cm/s, some crayfishes were swept away andcould not return to burrows because of the high water velocity.At 30 cm/s, most animals were swept away. We concludethat the appropriate water velocity for the suitability of artificialburrows and the immediate foraging area adjacent to the burrowsshould be as low as 5 cm/s. 相似文献
90.
The emulsifying properties of porcine sarcoplasmic protein (SP) with or without low-molecular weight surfactants were examined. The emulsifying activity (EA) of SP was weaker than that of sodium caseinate (CA), blood plasma (BP) and whey protein isolates at a protein concentration of 0.5–3%. Sodium chloride decreased the EA of SP. The EA of SP was about one quarter that of CA in the presence of 3% sodium chloride. As homogenization time increased, the EAs of SP and BP decreased. The EA of SP was not influenced by sucrose stearate ester (SE) with a hydrophilic-lipophilic balance (HLB) value of 16 (SE-16) but was decreased by those with HLB values of 5 and 1. Low-molecular weight surfactants such as SE-16, Tween 80 and sodium cholate improved the EA of SP with the two-step emulsification method: corn oil was previously emulsified with the surfactant before addition of SP and homogenization. In the case of the addition of SE-16 as primary emulsifier, the EA was about twice as high as that of SP alone. The same effect was shown in the emulsions formed by CA and soy protein isolate. These results indicate that the emulsifying properties of meat protein would be improved by the addition of a low-molecular weight surfactant in a two-step emulsification. 相似文献