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131.
Béjà O Aravind L Koonin EV Suzuki MT Hadd A Nguyen LP Jovanovich SB Gates CM Feldman RA Spudich JL Spudich EN DeLong EF 《Science (New York, N.Y.)》2000,289(5486):1902-1906
Extremely halophilic archaea contain retinal-binding integral membrane proteins called bacteriorhodopsins that function as light-driven proton pumps. So far, bacteriorhodopsins capable of generating a chemiosmotic membrane potential in response to light have been demonstrated only in halophilic archaea. We describe here a type of rhodopsin derived from bacteria that was discovered through genomic analyses of naturally occuring marine bacterioplankton. The bacterial rhodopsin was encoded in the genome of an uncultivated gamma-proteobacterium and shared highest amino acid sequence similarity with archaeal rhodopsins. The protein was functionally expressed in Escherichia coli and bound retinal to form an active, light-driven proton pump. The new rhodopsin exhibited a photochemical reaction cycle with intermediates and kinetics characteristic of archaeal proton-pumping rhodopsins. Our results demonstrate that archaeal-like rhodopsins are broadly distributed among different taxa, including members of the domain Bacteria. Our data also indicate that a previously unsuspected mode of bacterially mediated light-driven energy generation may commonly occur in oceanic surface waters worldwide. 相似文献
132.
Kozuma M Suzuki Y Torii Y Sugiura T Kuga T Hagley EW Deng L 《Science (New York, N.Y.)》1999,286(5448):2309-2312
Phase-coherent matter-wave amplification was demonstrated using Bose- Einstein-condensed rubidium-87 atoms. A small seed matter wave was created with coherent optical Bragg diffraction. Amplification of this seed matter wave was achieved by using the initial condensate as a gain medium through the superradiance effect. The coherence properties of the amplified matter wave, studied with a matter-wave interferometer, were shown to be locked to those of the initial seed wave. The active matter-wave device demonstrated here has great potential in the fields of atom optics, atom lithography, and precision measurements. 相似文献
133.
K Suzuki 《Science (New York, N.Y.)》1968,159(3822):1471-1472
The livers and spleens from three patients with cerebral G(M1)-gangliosidosis contained greatly increased concentrations of a mucopolysaccharide tentatively identified as keratan sulfate. The concentration of a very soluble sialomucopolysaccharide was also increased. Concentrations of these compounds were not increased in the viscera of patients with Tay-Sachs disease (G(M2)-gangliosidosis). G(M1)-gangliosidosis appears to be a combined cerebral gangliosidosis and visceral mucopolysaccharidosis. 相似文献
134.
Atropinesterase and cocainesterase of rabbit serum: localization of the enzyme activity in isozymes 总被引:2,自引:0,他引:2
Zymograms reveal a multiplicity of esterase isozymes in rabbit serum. Most of the staining activity is concentrated in a region of the gels just anodal to the albumins where six phenotypes (A, AF, F, M, P, and S) are distinguished. The atropinesterase activity is associated with phenotypes A and AF and appears to be restricted to a single isozyme, zone A. Cocainesterase activity is limited to isozyme S, a zone common to all phenotypes except M. 相似文献
135.
136.
Ryo Matsuda Katsumi Suzuki Akimasa NakanoTadahisa Higashide Masuyuki Takaichi 《Scientia Horticulturae》2011
We investigated the effects of altered source/sink ratio by leaf or fruit pruning on leaf photosynthetic characteristics and whole-plant growth of ‘Momotaro York’, a Japanese cultivar, and ‘Dundee’, a Dutch cultivar and verified a hypothesis for sink-limitation of plant growth proposed by Tanaka and Fujita (1974). Plants were grown hydroponically with a high-wire system in a greenhouse for 11 weeks. Light-saturated photosynthesis of young, fully expanded leaves measured at atmospheric CO2 partial pressure of 37 Pa and at an intercellular CO2 partial pressure of 20 Pa was not influenced by alteration of source/sink ratio for either cultivar. Although soluble sugars were accumulated in leaves under high source/sink conditions, the amount of ribulose-1,5-bisphosphate carboxylase/oxygenase, a rate-limiting factor for CO2-limited photosynthesis, was not affected by the altered source–sink balance. Net assimilation rate of a whole plant increased with decreasing source/sink ratio, but this can be accounted for by the changes in light interception per unit leaf area, without taking the source–sink relationship into consideration. It was concluded that the altered source/sink ratio did not change leaf photosynthetic capacity and the sink-limitation hypothesis cannot be applied to either cultivar under the conditions of the present study. 相似文献
137.
Ryo Matsuda Akimasa Nakano Dong-Hyuk AhnKatsumi Suzuki Ken-Ichiro YasubaMasuyuki Takaichi 《Scientia Horticulturae》2011
The aim of the present study was to elucidate how fruit growth was limited by the source and sink capacities in a Japanese (‘Momotaro York’) and a Dutch (‘Dundee’) tomato cultivar. The two cultivars were grown hydroponically with a high-wire system in greenhouses for 25 weeks, and the growth characteristics and sink strength of fruit were determined. Fruits were pruned to four (4F) or one (1F) per truss. The latter were used to determine potential fruit growth, an indicator of fruit sink strength. Growth was also determined under normal (LC) and enriched (HC, 700 μmol mol−1) CO2 concentrations to examine the effect of source enhancement on fruit production. In both cultivars under normal CO2, the growth rate of fruit pruned to 4F per truss was lower than that in 1F, indicating that maximum potential fruit growth was not achieved. Under HC conditions, fruit growth rate of ‘Dundee’ achieved in 4F trusses was lower than that in 1F. In ‘Momotaro York’ in HC, fruit growth in 4F trusses was close to potential. This implies that fruit growth was source-limited irrespective of CO2 concentrations in ‘Dundee’ cultivar while fruit growth in ‘Momotaro York’ under normal and enriched CO2 conditions was limited by source and sink strengths, respectively. Adjustments of cultural practices including increasing fruit number per truss and/or genetic approaches to enhancing fruit sink strength by breeding may improve fruit yields of Japanese cultivars under high source/sink conditions. 相似文献
138.
BACKGROUND: The occurrence of carboxylic acid amide (CAA)‐fungicide‐resistant Plasmopara viticola populations is becoming a serious problem in the control of grapevine downy mildew worldwide. RESULTS: The authors have developed a method, which utilises PCR‐RFLP, for the rapid detection of resistance to the CAA fungicide mandipropamid in P. viticola populations. With this method, a glycine‐to‐serine substitution at codon 1105 of the cellulose synthase gene PvCesA3 of CAA‐fungicide‐resistant P. viticola was easily detected, although no resistant P. viticola was detected from 398 isolates in Japan. CONCLUSION: It is proposed that the PCR‐RFLP method is a reliable tool for the rapid detection of CAA‐fungicide‐resistant P. viticola isolates. Only 4 h was required from the sampling of symptoms to the phenotyping of fungicide resistance. Copyright © 2011 Society of Chemical Industry 相似文献
139.
Spore-breaking capabilities of collembolans and their feeding habitat within sporocarps 总被引:2,自引:0,他引:2
To examine the relationship between the spore-breaking capability of collembolans and their localization within fungal sporocarps we investigated the proportion of broken spores in the feces of four collembolan species of the genus Hypogastrura using the spores of Hypsizygus marmoreus and analyzed the spatial distribution of the collembolan species within sporocarps as an index of their feeding habits. The collembolan species with a higher capability to break spores were observed more frequently from the spore-bearing surfaces of sporocarps. The collembolan species with a lower capability to break spores were found more frequently from the non-spore-bearing interiors of the sporocarps. These results suggest that the relative value of spores in the diet varied with the capability of collembolans to break spores. 相似文献
140.
Mizuno A Mitsuiki M Motoki M Ebisawa K Suzuki E 《Journal of agricultural and food chemistry》2000,48(8):3292-3297
The change in molecular structure of the soy protein samples as a result of the microbial transglutaminase treatment was studied using solid-state (13)C NMR spectroscopy and circular dichroism (CD), and the relation to the glass transition temperature (T(g)) was examined. From NMR measurements, the structure of the local region of the C(alpha) methine was observed to change, and the region had relatively high mobility. From CD measurements, the structural change seemed to be caused by the change in the secondary structure (disintegration of the beta-structure). By comparison with the T(g) of another protein, the state of the secondary structure of a protein was suggested to be a key in determining its T(g). 相似文献