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1.
Laminaria abyssalis occurs in deep water in tropical latitudes of the Brazilian coast (19° 23 S, 38° 28 W to 22° 54 S, 42° 13 09 W). Its life cycle has been completed in the laboratory in seven months using different conditions of light and temperature. The gametophytic stage required for growth the low photon flux density of 1.2 ± 0.3 µmol m–2 s–1 and 18 °C, while the juvenile and adult sporophytes needed 15 µmol m–2 s–1 and 18 °C. The sporophytes became fertile at 23 °C. Our results showed that light and temperature are the main factors regulating the growth and life history of this species under the culture conditions tested. 相似文献
2.
Die Verteilung chemisch induzierter achromatischer Läsionen und Brüche auf den Chromatiden menschlicher Leukozytenchromosomen 总被引:1,自引:0,他引:1
Günter Obe 《Chromosoma》1969,26(4):475-479
The intrachromatidal distributions of achromatic lesions (AL) and chromatid breaks (B) on 10 sections of equal length of the chromatids from the centromere to the distal end are investigated. Formally they can be described by Poisson-distributions. The maximum of the frequencies of AL and B is located in the distal half of the chromatids. The distributions are interpreted with restitutional action.
D 188. 相似文献
D 188. 相似文献
3.
G. Stotz P. de Vlaming H. Wiering A. W. Schram G. Forkmann 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1985,70(3):300-305
Summary In flower extracts of defined genotypes of Petunia hybrida, an enzyme activity was demonstrated which catalyses the hydroxylation of naringenin and dihydrokaempferol in the 3-position. Similar to the flavonoid 3-hydroxylases of other plants, the enzyme activity was found to be localized in the microsomal fraction and the reaction required NADPH as cofactor. A strict correlation was found between 3-hydroxylase activity and the gene Ht1, which is known to be involved in the hydroxylation of flavonoids in the 3-position in Petunia. Thus, the introduction of the 3-hydroxyl group is clearly achieved by hydroxylation of C15-intermediates, and the concomitant occurrence of the 3,4-hydroxylated flavonoids quercetin and cyanidin (paeonidin) in the presence of the functional allele Ht1 is due to the action of one specific hydroxylase catalysing the hydroxylation of common precursors for both flavonols and anthocyanins. 相似文献
4.
Cecilia PC Soh Alastair SR Donald James Feeney Walter TJ Morgan Winifred M Watkins 《Glycoconjugate journal》1989,6(3):319-332
The tetrasaccharides GalNAcß1-4[NeuAc2-3]Galß1-4Glc and GalNAcß1-4[NeuAc2-3]Galß1-4GlcNAc were synthesised by enzymic transfer of GalNAc from UDP-GalNAc to 3-sialyllactose (NeuAc2-3Galß1-4Glc) and 3-sialyl-N-acetyllactosamine (NeuAc2-3Galß1-4GlcNAc). The structures of the products were established by methylation and1H-500 MHz NMR spectroscopy. In Sda serological tests the product formed with 3-sialyl-N-acetyllactosamine was highly active whereas that formed with 3-sialyllactose had only weak activity. 相似文献
5.
Günter Obe 《Chromosoma》1971,33(4):403-408
The interchromosomaldistributions of spontaneous achromatic lesions (AL) and chromatid breaks (B) in human leukocytes in vitro are non-random. There are too many aberrations in chromosome No. 3. The non-random intrachromosomal distributions of AL and B are very similar to the distributions of chemically induced aberrations of the same type. 相似文献
6.
Toshikazu Oki Akihiro Yoshimoto Tatsuo Ogasawara Seiji Sato Akira Takamatsu 《Archives of microbiology》1976,107(2):183-187
The occurrence of adenosine 5-triphosphate-3-diphosphate-synthesizing activity was detected in five strains of actinomycetes; Streptomyces morookaensis, Streptomyces aspergilloides, Streptomyces hachijoensis, Actinomyces violascens and Streptoverticillium septatum, out of 825 strains of actinomycetes, bacteria, fungi and imperfecti. Purine nucleotide pyrophosphotransferase were extracellularly excreted associating with the cell growth, and were purified partially or to apparent homogeniety from the culture filtrate. The enzymes are a monomeric protein with a molecular weight of 18000–26000 and synthesize adenosine, guanosine and inosine 5-phosphate (mono, di or tri)-3-diphosphate such as pApp, ppApp, pppApp, pGpp, ppGpp, pppGpp and pppIpp by transferring a pyrophosphoryl group from the 5-position of ATP, dATP and pppApp to the 3-position of purine nucleotides in the presence of a divalent cation and in alkaline state.Abbreviations pppApp
adenosine 5-triphosphate 3-diphosphate
- ppApp
adenosine 5-diphosphate 3-diphosphate
- pApp
adenosine 5-monophosphate 3-diphosphate
- pppGpp
guanosine 5-triphosphate 3-diphosphate 相似文献
7.
In the present paper we describe the synthesis of Sepharose-boundN-(5-phosphopyridoxyl)-amino-oxyacetic acid,N-(5-phosphopyridoxyl)-canaline, andN-(5-phosphopyridoxyl)-,-diaminobutyric acid (Seph-DAB-PLP), designed for binding specifically brain glutamate decarboxylase (GAD). The three Sepharose-N-(phosphopyridoxyl)-amino acids were capable of binding GAD from a mouse brain soluble preparation. The enzyme can be purified up to 25-fold in one step by affinity chromatography on Seph-DAB-PLP.Part of this work was presented at the VI Meeting of the American Society for Neurochemistry, Mexico City, March 10–14, 1975. 相似文献
8.
Rabbit anti-mouse-Ia serum was raised against Ia specificities present in CBAJH (H-2
k) serum. This xenogeneic antiserum was considered to react with similar specificities to those detected by mouse anti-Iak alloantisera and more evidence is now presented for this contention. By absorption, the xenogeneic antiserum was found to react with spleen, lymph node, bone marrow, and thymus, reactions similar to that found with the allogeneic anti-Iak antiserum. Furthermore, red cells, platelets, brain, kidney, and liver could not absorb the activity from the xenogeneic antiserum, demonstrating the selective tissue distribution of the antigens reactive with this serum. This reactive population was previously shown to consist of B cells and a subpopulation of T cells. In a backcross study of (C57BL/6 × A)F1 × C57BL/6, the rabbit anti-Ia and mouse anti-Ia reactions were found to segregate together, and some evidence for the genetic regulation of the expression of Ia specificities was also found. By direct testing, and by absorption testing using a number of strains, the xenogeneic antiserum was shown to contain high titers of antibody to Ia.1, 3, 7, 15, and 17; lower titers to Ia.19, and 22; little antibody to Ia.18, and no reaction for the private specificity Ia. 2, although the multiple absorptions required to define these specificities may have observed some reactions. The data indicate that the xenogeneic and allogeneic anti-Iak antisera recognize similar Ia determinants, which map to theLA, IE andIC subregions of theH-2 complex. These have been given the same specificity designation as the allogeneic specificities, but they are separately identified by a prime ('). 相似文献
9.
The effect of inorganic phosphate, ADP, ATP, and their analogues on the rate of labeling of F1-ATPase by 7-chloro-4-nitrobenzo-2-oxa-1,3-diazole (NBD-Cl) and phenylglyoxal have been investigated. Analysis of the kinetic data indicate that the labeled functional groups of the essential tyrosine and arginine residues respectively are both located at the catalytic site of F1. The active phenolic group of tyrosine is located closer to the bound inorganic phosphate or the -phosphate group than the - and -phosphate groups of the bound ATP at the catalytic site, whereas the guanidinium group of arginine is located closer to the - and -phosphate groups of the bound ATP than to its -phosphate group or the bound inorganic phosphate. The kinetically deduced dissociation constants are 1.3 mM and 210 µM for the inorganic phosphate and ADP respectively bound to this catalytic site. Labeling the essential tyrosine residue by NDB-Cl has been found to facilitate subsequent labeling of the essential arginine residue by phenylglyoxal.Abbreviations NBD-Cl
7-chloro-4-nitrobenzo-2-oxa-1,3-diazole (this compound has been named 4-chloro-7-nitro-benzofurazan and abbreviated NBf-Cl elsewhere)
- DTT
dithiothreitol
- EDTA
ethylenediaminetetraacetic acid
- Pi
inorganic phosphate
- PEP
phosphoenolpyruvate
- ADPCP
,-methylene-adenosine 5-triphosphate
- AMPCP
,-methylene-adenosine 5-diphosphate
- Hepes
N-2-hydroxyethylpiperazine-N-2-ethanesulfonic acid
- Tris
2-amino-2(hydroxymethyl)-1,3-propanediol 相似文献
10.
Summary A new method for measuring structural change in sets of species which have been subjected to natural or experimental perturbation is developed and is shown to be superior to static diversity and evenness measures for this purpose. Three parameters, H, J, and X;} are shown to provide necessary and sufficient information on the severity of a perturbation as well as the uniformity of its effect on all species in the set. When positive and negative changes in species abundance are considered separately, the method is sensitive to compensatory changes which are not detected by static measures.The parameters are then calculated for some data sets on polluted and unpolluted fish communities in second and third order streams from the Clemons Fork watershed in eastern Kentucky. Results indicate that H, the diversity of change over two sampling seasons, is high for perturbed and unperturbed systems, but J the eveness of change is lower for the communities which were polluted in the second sampling season. Severe pollution results in the suppression of most major fish species, whereas more moderate pollution results in a large number of compensatory changes. The biological basis for such an outcome is discussed, and the notion of these three parameters as the vital signs of a healthy ecosystem is presented. 相似文献
11.
Turgor (p) and osmotic potential (s) in epidermal and mesophyll cells, in-situ xylem water potential (-xyl) and gas exchange were measured during changes of air humidity and light in leaves ofTradescantia virginiana L., Turgor of single cells was determined using the pressure probe. Sap of individual cells was collected with the probe for measuring the freezing-point depression in a nanoliter osmometer. Turgor pressure was by 0.2 to 0.4 MPa larger in mesophyll cells than in epidermal cells. A water-potential gradient, which was dependent on the rate of transpiration, was found between epidermis and mesophyll and between tip and base of the test leaf. Step changes of humidity or light resulted in changes of epidermal and mesophyll turgor (p-epi, p-mes) and could be correlated with the transpiration rate. Osmotic potential was not affected by a step change of humidity or light. For the humidity-step experiments, stomatal conductance (g) increased with increasing epidermal turgor.g/p-epi appeared to be constant over a wide range of epidermal turgor pressures. In light-step experiments this type of response was not found and stomatal conductance could increase while epidermal turgor decreased.Symbols
E
transpiration
-
g
leaf conductance
- w
leaf/air vapour concentration difference
- -epi
water potential of epidermal cells
- -mes
water potential of mesophyll cells
- -xyl
water potential of xylem
- p-epi
turgor pressure of epidermal cells
- p-mes
turgor pressure of mesophyll cells
- s-epi
osmotic potential of epidermal cells
- s-mes
osmotic potential of mesophyll cells 相似文献
12.
Jagroop S. Dahiya 《Plant and Soil》1991,134(2):297-304
A broad-host-range plasmid (pEA2-21) containing a Bradyrhizobium sp (F-4) nod DABC-lacZ translation fusion was constructed and used to monitor nod gene expression in response to pigeonpea root exudate. Two nod-inducing compounds were isolated and identified. Spectral analysis using ultraviolet absorption, infrared spectra, proton nuclear magnetic resonance, and mass spectrometry showed that the two inducers were 5,4-dihydroxy-6-(3-methyl-2-butenyl)-2, 2-dimethyl pyrano-[5, 6:7, 8]-flavanone (cajaflavanone) and 2,4,5-trihydroxy-5-isopentenyl-6, 7-dimethylchromene iso-flavanone (cajanone). When pEA2-21 was introduced into Rhizobium trifolii and R. meliloti cajanone and cajaflavanone did not induce nod gene indicating that specificity of induction appears to be influenced by the host-strain genome. 相似文献
13.
N Nakada K Yoshinaga A Ishihama H Nagasawa-Fujimori 《Molecular & general genetics : MGG》1982,188(2):173-178
Summary On exposure to high temperature of a temperature-sensitive RNA polymerase subunit (rpoC92) mutant of Escherichia coli, selective reduction was observed in the rate of synthesis of a group of proteins including RNA polymerase subunit. The finding that the synthesis of subunit but not subunit was specifically repressed in this mutant grown at non-permissive temperature indicates that the functionally intact RNA polymerase is required for the synthesis of subunits be coordinated. In addition, the assembly of newly synthesized RNA polymerase subunits was inefficient in this mutant at the steps where altered subunit was involved, and the unassembled enzyme subunits were rapidly and preferentially degraded. During recovery to non-restricted growth, the synthesis of both and subunits was transiently enhanced in parallel leading to recovery of the intracellular concentration of functional RNA polymerase. 相似文献
14.
Zusammenfassung Serumproben von 1322 Blutspendern aus Hessen, 40 Familien mit 89 Kindern, 20 Mutter-Kind-Kombinationen und 268 Sera einer Bantupopulation aus Portugiesisch Angola wurden mit einer modifizierten Technik der Hochspannungs-Dünnschichtelektrophorese auf Agarosegel hinsichtlich des C3-Polymorphismus untersucht. Die Genfrequenzen für Weiße (C3S=0.779, C3F=0.215) und Neger (C3S=0.95, C3F=0,048) stimmen gut mit den Werten anderer Autoren überein. Insgesamt ließen sich bei Weißen 9 Phänotypen sicher abgrenzen, bei Negern 3. Familienstudien bestätigten den für die Allele C3S und C3F angenommenen Vererbungsmodus (autosomal codominant) ausnahmslos. Die Frage der Lagerungsstabilität des C3 wurde abschließend untersucht.
Investigations on C3-polymorphism ( 1c-Globulin)Gene frequencies and family studies in blood donors from Hessen and a Bantu population
Summary Serum samples of 1322 unrelated individuals from Hessen (Germany), 40 families with 89 children, 20 mother-child-combinations and 268 sera of a Bantu population from Angola were examined for C3 polymorphism using a modified technique of high voltage agarose gel electrophoresis. The gene frequencies for Caucasians (C3S=0.779, C3F=0.215) and negroes (C3S=0.95, CF=0.048) are in good accordance with those obtained by other authors. In total 9 different phenotypes were observed in Caucasians, 3 phenotypes in negroes. Family studies verify the supposed way of inheritance (autosomal codominant for C3S and C3F) without exception. Finally the problem of C3-inactivation by storage was investigated.相似文献
15.
Mr. A. Lees Dr. L. L. Sarliève Dr. N. M. Neskovic Dr. M. Wintzerith P. Mandel 《Neurochemical research》1977,2(1):11-25
Brain composition and developmental changes were investigated in mice homozygous for the locus dwarf, and characterized by a reduced level of growth hormone, thyroid stimulating hormone, and prolactin, and by secondary hypothyroidism. The difference in adult brain weight (–32%) between the dwarf and the normal mice was not found to parallel the difference in body weight (–71%), whereas the differences in the weight of the liver (–79%) and that of the kidney (–75%) did. Several biochemical parameters of brain development were assayed in dwarf and normal mice between the ages of 15 and 210 days. Levels of cerebrosides, sulfatides, gangliosides, phospholipids, cholesterol, protein, and RNA (per gram wet weight) were the same for the dwarf and the controls, but the net difference in total brain DNA was less than the net total brain RNA difference (–11% vs. –27%). Total brain lipids (absolute quantities) were the same at 15 days. The difference was –37% by the 50th day, and remained constant thereafter. No change in the specific activity of 2,3-cyclic nucleotide 3-phosphohydrolase or 3-phosphoadenosine-5-phosphosulfate: galactocerebroside sulfotransferase was observed. These data suggest that the regulation of the development of brain structures is maintained, but the level of the synthesis of the various brain constituents is reduced in proportion to the brain weight. The development of the dwarf brain seems to proceed harmoniously.Abbreviations used PAPS
3-phosphoadenosine-5-phosphosulfate
- PAPS-CST
3-phosphoadenosine-5-phosphosulfate:galactocerebroside sulfotransferase
- CNP
2, 3-cyclic nucleotide 3-phosphohydrolase
- Neu NAc
N-acetylneuraminic acid
This paper is part of the Doctorat d'Etat thesis of L. L. Sarliève. 相似文献
16.
Both qualitative and quantitative differences in the minor nucleotide constituents of rRNA from normally grown and from etiolated wheat plants (Triticum aestivum L.) were established. Using different degradation methods and separation techniques the 18S+26S RNA of 8-day-old wheat seedlings grown in the light was found to contain 5-methylcytidine, 3-methylcytidine, 5-methyluridine, 3-methyluridine, 5-carboxymethyluridine, 1-methyladenine, N-methyladenine, 5-hydroxymethylcytidine, O2-methyluridine, O2-methylcytidine, pseudouridine, O2-methylpseudouridine, N2,N2-dimethylguanine, 1-methylguanine, ribothymidine and some unknown minor constituents. On the other hand, there were only a few minor nucleotides in the rRNA of etiolated wheat seedlings. Cycloheximide, a cytoplasmic protein synthesis inhibitor, simulated etiolation in that it reduced the number of minor nucleotides in rRNA, whereas chloramphenicol, a chloroplast protein synthesis inhibitor, had no significant effect on the minor nucleotide content of rRNA. This finding suggests that illumination may cause de novo synthesis of cytoplasmic modifying enzymes leading to the formation of highly modified rRNAs.Abbreviations m6A
N6-methyladenine
- m1A
1-methyladenine
- 5hmc
5-hydroxymethylcytidine
- Cm
O2-methylcytidine
- m5C
5-methylcytidine
- m3C
3-methylcytidine
- m1G
1-methylguanine
- m
2
2
G
N2, N2-dimethylguanine
-
pseudouridine
- m
O2-methylpseudouridine
- Um
O2-methyluridine
- m3U
3-methyluridine
- m5U
5-methyluridine
- cm5U
5-carboxymethyluridine
- rT
ribothymidine
- Pur
purine
- Pyr
pyrimidine
- RNase
ribonuclease
- UV
ultra violet
- p
phosphate 相似文献
17.
V. A. Wagner T. A. Schild H. Geldermann 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1994,89(1):121-126
For the detection of polymorphisms within the 5-flanking region of the -lactoglobulin (-LG) -encoding gene a nucleotide sequence containing 795 bp of the promoter and 59 bp of exon I was cloned and sequenced. After comparing the sequence from the DNA of 11 diverse cows (different breeds and milk-protein yields), 14 singlebp substitutions were identified within the 5-flanking region and two in the 5-untranslated region (5-UTR) of exon I. Some of the variants are located in potential binding sites for trans-acting factors or in the 5-UTR. A PCR-based RFLP analysis was performed, and the genotypes of an additional 60 cows were identified at five variable 5-flanking sites. The results reveal three frequent combinations between the A and B alleles of the protein-coding region and the novel 5-flanking DNA variants. This finding may explain the differences of the protein-variant-dependent -LG synthesis (A>B) observed in vivo. A sequence comparison of the bovine and ovine promoters reveals an homology of 92.8% and shows a higher degree of conservation between positions -600 and -300. 相似文献
18.
G. Mattson E. Conklin S. Desai G. Nielander M. D. Savage S. Morgensen 《Molecular biology reports》1993,17(3):167-183
The various aspects of chemical crosslinking are addressed. Crosslinker reactivity, specificity, spacer arm length and solubility characteristics are detailed. Considerations for choosing one of these crosslinkers for a particular application are given as well as reaction conditions and practical tips for use of each category of crosslinkers.Abbreviations ABH
azidobenzoyl hydrazide
- ANB- NOS
N-5-azido-2-nitrobenzoyloxysuccinimide
- ASIB
1-(p-azidosalicylamido)-4-(iodoacetamido)butane
- ASBA
4-(p-azidosalicylamido)butylamine
- APDP
N-[4-(p-azidosalicylamido) butyl]-3(2-pyridyldithio)propionamide
- APG
p-azidophenyl glyoxal monohydrate
- BASED
bis-[-(4-azidosalicylamido)ethyl] disulfide
- BMH
bismaleimidohexane
- BS3
bis(sulfosuccinimidyl) suberate
- BSOCOES
bis[2-(succinimidooxycarbonyloxy)ethyl]sulfone
- DCC
N,N-dicyclohexylcarbodiimide
- DFDNB
1,5-difluoro-2,4-dinitrobenzene
- DMA
dimethyl adipimidate·2HCl
- DMP
dimethyl pimelimidate·2HCl
- DMS
dimethyl suberimidate·2HCl
- DPDPB
1,4-di-(3,2-pyridyldithio)propionamido butane
- DMF
dimethylformamide
- DMSO
dimethylsulfoxide
- DSG
disuccinimidyl glutarate
- DSP
dithiobis(succinimidylpropionate)
- DSS
disuccinimidyl suberate
- DST
disuccinimidyl tartarate
- DTSSP
3,3-dithiobis (sulfosuccinimidylpropionate)
- DTBP
dimethyl 3,3-dithiobispropionimidate·2HCl
- EDC or EDAC
1-ethyl-3-(3-dimethylaminopropyl)carbodimide hydrochloride
- EDTA
ethylenediaminetetraacetic acid disodium salt, dihydrate
- EGS
ethylene glycolbis(succinimidylsuccinate)
- GMBS
N--maleimidobutyryloxysuccinimide ester
- HSAB
N-hydroxysuccinimidyl-4-azidobenzoate
- HEPES
4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid
- MBS
m-maleimidobenzoyl-N-hydroxysuccinimide ester
- MES
4-morpholineethanesulfonic acid
- NHS
N-hydroxysuccinimide
- NHS-ASA
N-hydroxysuccinimidyl-4-azidosalicylic acid
- PMFS
phenylmethylsulfonyl fluoride
- PNP-DTP
p-nitrophenyl-2-diazo-3,3,3-trifluoropropionate
- SAED
sulfosuccinimidyl 2-(7-azido-4-methylcoumarin-3-acetamide) ethyl-1,3-dithiopropionate
- SADP
N-succinimdyl (4-azidophenyl)1,3-dithiopropionate
- SAND
sulfosuccinimidyl 2-(m-azido-o-nitrobenzamido)-ethyl-1,3-dithiopropionate
- SANPAH
N-succinimidyl-6(4-azido-2-nitrophenyl-amino)hexanoate
- SASD
sulfosuccinimidyl 2-(p-azidosalicylamido)ethyl-1,3-dithiopropionate
- SATA
N-succinimidyl-S-acetylthioacetate
- SDBP
N-hydroxysuccinimidyl-2,3-dibromopropionate
- SIAB
N-succinimidyl(4-iodoacetyl)aminobenzoate
- SMCC
succinimidyl 4-(N-maleimidomethyl)cyclohexane-1-carboxylate
- SMPB
succinimidyl 4-(p-maleimidophenyl) butyrate
- SMPT
4-succinimidyloxycarbonyl--methyl--(2-pyridyldithio)-toluene
- sulfo-BSOCOES
bis[2-sulfosuccinimidooxycarbonyloxy) ethyl]sulfone
- sulfo-DST
disulfosuccinimidyl tartarate
- sulfo-EGS
ethylene glycolbis(sulfosuccinimidylsuccinate)
- sulfo-GMBS
N--maleimidobutyryloxysulfosuccinimide ester
- sulfo-MBS
m-maleimidobenzoyl-N-hydroxysulfosuccinimide ester
- sulfo-SADP
sulfosuccinimidyl(4-azidophenyldithio)propionate
- sulfo-SAMCA
sulfosuccinimidyl 7-azido-4-methylcoumarin-3-acetate
- sulfo-SANPAH
sulfosuccinimidyl 6-(4-azido-2-nitrophenylamino)hexanoate
- sulfo-SIAB
sulfosuccinimidyl(4-iodoacetyl)aminobenzoate
- sulfo-SMPB
sulfo-succinimidyl 4-(p-maleimidophenyl)butyrate
- sulfo-SMCC
sulfosuccinimidyl 4-(N-maleimidomethyl)cyclohexane-1-carboxylate
- SPDP
N-succinimidyl 3-(2-pyridyldithio)propionate 相似文献
19.
J. S. Huebner 《The Journal of membrane biology》1978,39(2-3):97-132
Summary Flash illumination alters the voltage across bilayer lipid membranes in the presence of certain cyanine dyes. The waveforms of the photo-voltage vary systematically with dye structure and imposed transmembrane voltage. Experimental results are reported for 27 positively charged cyanine dyes, primarily oxazole derivatives, using lecithin/oxidized cholesterol bilayer membranes and 10-mm sodium chloride solutions. Several dyes do not induce any photo-voltages. Examples are 3,3 diethyl 9 ethyl 2,2 oxacarbocyanine iodide, 3,3 diethyl 2 oxa 2 thiacyanine iodide, and 3,3 dimethyl 2,2 indocarbocyanine iodide. Several dyes, when added to one side of the membranes, induce monophasic waveforms. Examples are 3,3 dimethyl 2,2 oxacarbocyanine chloride, and 3,4,3,4 tetramethyl 2,2 oxazalinocarbocyanine iodide. Other dyes induce a photo-voltage only if transmembrane voltages are imposed. These waveforms are biphasic with some dyes (3,3 diethyl 2,2 oxacarbocyanine iodide, for example) and monophasic with other dyes (3,3 dibutyl 2,2 oxacarbocyanine iodide, for example).The photo-voltage waveforms are explained by models that consider the movement of charged dye molecules within the membrane, following optical excitation. The dye movements are probably induced through charge rearrangements in the dye associated with long-lived triplet states, isomerization, or through excimer formation. These results provide information on the location and orientation of the dye molecules within bilayer membranes. The variations which occur in the waveforms with applied voltage indicate that these membranes are fluid in the direction perpendicular to the membrane plane. 相似文献
20.
Summary Imidazolides of dinucleotides such as ImpApA can be formed from the corresponding dinucleotides in a two-stage process, which gives up to 15% yields under potentially prebiotic conditions. First a solution of the dinucleotide and sodium trimetaphosphate is dried out at constant temperature and humidity. This produces polyphosphates such as pnApA in excellent yield (80%). The products are dissolved in water, imidazole is added, and the solution is dried out again. This yields the 5-phosphorimidazolides.Abbreviations P3!
trimetaphosphate
- A
adenosine
- U
uridine
- EDTA
ethylenediaminetetraacetic acid
- Ap
adenosine 2(3)-phosphate
- Ap!
adenosine cyclic 2:3-phosphate
- pA
adenosine 5-phosphate
- pA2p
adenosine 2, 5-diphosphate
- pA3p
adenosine 3, 5-diphosphate
- pAp!
5-phospho-adenosine cyclic 2:3-phosphate
- ATP
adenosine 5-triphosphate
- ImpA
adenosine 5-phosphorimidazolide
- A2pA
adenylyl-[25]-adenosine
- A3pA
adenylyl-[35]-adenosine
- A2pU
adenylyl-[25]-uridine
- A3pU
adenylyl-[35]-uridine
- pA2pA
5-phosphoadenylyl-[25]-adenosine
- pA3pA
5-phospho-adenylyl-[35]-adenosine
- pA2pU
5-phospho-adenylyl-[25]-uridine
- pA3pU
5-phospho-adenylyl-[35]-uridine
- pApN (N= A, U)
5-phosphate of a dinucleoside phosphate
- pnApN (N = A, U; n = 2, 3, 4.)
5-polyphosphate of a dinucleoside phosphate
- ImpA2pA
imidazolide of pA2pA
- ImpA3pA
imidazolide of pA3pA
- ImpA2pU
imidazolide of pA2pU
- ImpA3pU
imidazolide of pA3pU
- ImpApN
imidazolide of pApN 相似文献