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1.
Kemp Graham J. Manners David N. Clark Joseph F. Bastin Mark E. Radda George K. 《Molecular and cellular biochemistry》1998,184(1-2):249-289
After discussing approaches to the modelling of mitochondrial regulation in muscle, we describe a model that takes account, in a simplified way, of some aspects of the metabolic and physical structure of the energy production/usage system. In this model, high-energy phosphates (ATP and phosphocreatine) and low energy metabolites (ADP and creatine) diffuse between the mitochondrion and the myofibrillar ATPase, and can be exchanged at any point by creatine kinase. Creatine kinase is not assumed to be at equilibrium, so explicit account can be taken of substantial changes in its activity of the sort that can now be achieved by transgenic technology in vivo. The ATPase rate is the input function. Oxidative ATP synthesis is controlled by juxtamitochondrial ADP concentration. To allow for possible functional coupling between the components of creatine kinase associated with the mitochondrial adenine nucleotide translocase and the myofibrillar ATPase, we define parameters and that set the fraction of the total flux carried by ATP rather than phosphocreatine out of the mitochondrial unit and into the ATPase unit, respectively. This simplification is justified by a detailed analysis of the interplay between the mitochondrial outer membrane porin proteins, mitochondrial creatine kinase and the adenine nucleotide translocase. As both processes of possible coupling are incorporated into the model as quantitative parameters, their effect on the energetics of the whole cell model can be explicitly assessed. The main findings are as follows: (1) At high creatine kinase activity, the hyperbolic relationship of oxidative ATP synthesis rate to spatially averaged ADP concentration at steady state implies also a near-linear relationship to creatine concentration, and a sigmoid relation to free energy of ATP hydrolysis. At high creatine kinase activity, the degree of functional coupling at either the mitochondrial or ATPase end has little effect on these relationships. However, lowering the creatine kinase activity raises the mean steady state ADP and creatine concentrations, and this is exaggerated when or is near unity (i.e. little coupling). (2) At high creatine kinase activity, the fraction of flow at steady state carried in the middle of the model by ATP is small, unaffected by the degree of functional coupling, but increases with ADP concentration and rate of ATP turnover. Lowering the creatine kinase activity raises this fraction, and this is exaggerated when or is near unity. (3) Both creatine and ADP concentrations show small gradients decreasing towards the mitochondrion (in the direction of their net flux), while ATP and phosphocreatine concentration show small gradients decreasing towards the myosin ATPase. Unless = 0 (i.e. complete coupling), there is a gradient of net creatine kinase flux that results from the need to transform some of the adenine nucleotide flux at the ends of the model into creatine flux in the middle; the overall net flux is small, but only zero if = . A reduction in cytosolic creatine kinase activity decreases ADP concentration at the mitochondrial end and increases it at the ATPase end. (4) During work-jump transitions, spatial average responses exhibit exponential kinetics similar to those of models of mitochondrial control that assume equilibrium conditions for creatine kinase. (5) In response to a step increase in ATPase activity, concentration changes start at the ATPase end and propagate towards the mitochondrion, damped in time and space. This simplified model embodies many important features of muscle in vivo, and accommodates a range of current theories as special cases. We end by discussing its relationship to other approaches to mitochondrial regulation in muscle, and some possible extensions of the model. 相似文献
2.
T. Hartmund H. Gesser 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》1995,165(3):219-229
With focus on metabolism not depending on contractility in myocardial tissue from rainbow trout, Oncorhynchus mykiss, the effects of high CO2 on lactate production, phosphocreatine, creatine, ATP, ADP, AMP and intracellular pH were examined under a blockage of cell respiration either alone or in combination with a glycolytic inhibition. Irrespective of metabolic interventions, a change in CO2 from 1 to either 11 or 5% of the gas mixture perfusing the muscle bath with 15 mmol·l-1 HCO
-
3
caused a drop of intracellular pH from 7.4 to either 6.5 or 7.0, respectively. An elevation of CO2 to 11% diminished the rate of anaerobic lactate formation and slightly lowered anaerobic energy degradation. The further addition of 1 mmol·l-1 iodoacetate to inhibit glycolysis strongly enhanced the tendency of acidosis to lower energy degradation. Moreover, iodoacetate induced a parallel decrease in ATP and total concentration of phosphorylated adenylates and an increase in resting tension. These effects were all substantially dampened by acidosis and could not immediately be related to tissue content of energy-rich phosphates. Tentatively, the depression of resting tension was the prime effect and a cause of the other effects acidosis. However, these were not affected by an inhibition of resting tension development with 2,3-butadione monoxime. The results suggest that glycolysis protects the anaerobic myocardium also by means not immediately related to tissue energy state. Acidosis exerts a similar protection, which is marginal as long as glycolysis is fully active, but substantial with an inhibited glycolysis.Abbreviations
Cr
t
total tissue concentration of creatine
- G
PCr
energy liberated per mol PCr hydrolyzed
-
IAA
iodoacetate
-
PCr
phosphocreatine
-
PE
total tissue concentration of energy-rich phosphate bonds
-
pH
i
intracellular pH
-
P
i
inorganic phosphate
-
TAN
total tissue concentration of phosphorylated adenylates
- 2,3-BDM
2,3-butadione monoxime
-
SE
standard error of the mean 相似文献
3.
Sperlágh Beáta Illes Peter Gerevich Zoltán Köfalvi Attila 《Neurochemical research》2001,26(8-9):951-957
The temperature-dependence of ATP release and contraction response evoked by different agonists were investigated in superfused guinea-pig vas deferens. -Adrenoceptor agonists, i.e. noradrenaline (300 M), and -methyl-noradrenaline (300 M), increased the basal ATP outflow, measured by the luciferin-luciferase assay, and induced biphasic contractile response. Cooling the bath temperature to 12°C almost completely inhibited ATP release and twitch contraction evoked by -adrenoceptor agonists, whereas the phasic contraction remained unaffected. In contrast, twitch contraction and subsequent ATP release induced by ,-methylene-ATP, a selective P2 receptor agonist (100 M), was not reduced by low temperature. The ectoATPase activity, measured by HPLC technique was not significantly different at 37°C and 12°C. Nifedipine (1 M), the voltage sensitive Ca2+ channel blocker eliminated ,-methylene-ATP evoked twitch contraction but not ATP release. In conclusion, -adrenoceptor and P2 receptor agonists utilize distinct mechanisms to elicit ATP release and contraction: -adrenoceptor-mediated ATP release and contraction is temperature-dependent, indicating the involvement of a carrier-mediated process in it, whereas P2x purinoceptor evoked ATP release and twitch is mediated by a different mechanism. 相似文献
4.
Claire D. F. Parsons 《Culture, medicine and psychiatry》1984,8(1):71-93
Idioms of distress refers to the popular expression of emotional tension that arises in the relationship between sickness and kinship. By reference to case studies and discussions among the Polynesian people of Tonga, the author shows where such tension arises and how it influences the sickness process. Sickness is necessarily a collective phenomenon which can best be understood not simply as a clinical event, but as an experience that is part of the experience of family. Various ways of expressing distress as a reflexive encounter between personal and cultural meaning systems are reviewed, as are several new concepts such as doing sickness as kinship, and turning in the process of decision making in the kinship management of sickness. The explanatory models of sickness in Tonga are shown to encompass culturally sanctioned expressions of distress as part of the adaptive coping mechanisms in that society. Distress frequently emerges in somatic form, as a number of studies have shown. However, the author emphasizes the kinship meaning of sickness, kinship management and sickness therapy, the adaptive process of idiomatic expressions of distress, which are expanded here and offered as potential avenues for elaboration in other cultural milieu. Two aspects of the notion idioms of distress are noted, and the phenomenon is understood as a process which acts as a prime mover in social change. 相似文献
5.
3-O-(4-benzoyl)benzoyl ATP (BzATP) was used as a photoaffinity analog of ATP to label potential ATP receptors in ciliated cells. Like ATP, without photoactivation, BzATP stimulated the ciliary beat frequency in tissue culture up to threefold. Irradiation of intact cells in the presence of [-32P]BzATP followed by SDS-PAGE and autoradiography revealed two labeled proteins with molecular masses of 46 and 96 kDa (p46 and p96). Photolabeling of both proteins was susceptible to digestion with trypsin, implying that the labeled proteins are at least partially exposed on the extracellular surface of the plasma membrane. The dependence of 32P incorporation in both proteins on [-32P]BzATP concentration was similar. Labeling of p46 but not p96 required Ca2+ or Mg2+. Various nucleotides stimulated the ciliary frequency, and inhibited the photolabeling of p46 and p96. The rank order of apparent affinity for p46 is: ATP ÃDP>GTPS>ADP S, UTP, 2MeSATP, AMP-PNP >AMP-PCP>AMP>adenosine; for p96 it is: ADPADP S ATP AMP-PCP, AMP-PNP>GTPS AMP>2MeSATP, UTP, adenosine. The rank of stimulation of ciliary beat frequency is: ADPS, UTP 2MeSATP, GTPS, AMP-PNP, ATPADP>AMPPCP>adenosine>AMP. These results suggest the involvement of p46 in the stimulatory effect of extracellular ATP on the ciliary beat, as a P2 purinoceptor. On the other hand, p96 may represent a P2 purinoceptor or an ectonucleotidase.This work was supported by grants (to Z.P. and to V.S-B.) from the Fund for Basic Research administered by the Israel Academy of Science and Humanities. 相似文献
6.
Ben A. Bulthuis Gregory M. Koningstein Adriaan H. Stouthamer Henk W. van Verseveld 《Antonie van Leeuwenhoek》1993,63(1):1-16
The magnitude of the proton motive force (p) and its constituents, the electrical () and chemical potential (-ZpH), were established for chemostat cultures of a protease-producing, relaxed (rel
–) variant and a not protease-producing, stringent (rel
+) variant of an industrial strain ofBacillus licheniformis (respectively referred to as the A- and the B-type). For both types, an inverse relation of p with the specific growth rate was found. The calculated intracellular pH (pHin) was not constant but inversely related to . This change in pHin might be related to regulatory functions of metabolism but a regulatory role for pHin itself could not be envisaged. Measurement of the adenylate energy charge (EC) showed a direct relation with for glucose-limited chemostat cultures; in nitrogen-limited chemostat cultures, the EC showed an approximately constant value at low and an increased value at higher . For both limitations, the ATP/ADP ratio was directly related to .The phosphorylation potential (G'p) was invariant with . From the values for G'p and p, a variable H+/ATP-stoichiometry was inferred: H+/ATP=1.83+0.52µ, so that at a given H+/O-ratio of four (4), the apparent P/O-ratio (inferred from regression analysis) showed a decline of 2.16 to 1.87 for =0 to max (we discuss how more than half of this decline will be independent of any change in internal cell-volume). We propose that the constancy of G'p and the decrease in the efficiency of energy-conservation (P/O-value) with increasing are a way in which the cells try to cope with an apparent less than perfect coordination between anabolism and catabolism to keep up the highest possible with a minimum loss of growth-efficiency. Protease production in nitrogen-limited cultures as compared to glucose-limited cultures, and the difference between the A- and B-type, could not be explained by a different energy-status of the cells.Abbreviations CCCP
carbonylcyanide-p-trichloromethoxyphenylhydrazone
- DW
dry weight of biomass
- F
Faraday's constant, 96.6 J/(mV × mol)
- Fo
chemostat outflow-rate (ml/h)
- FCCP
carbonylcyanide-p-trifluoromethoxyphenylhydrazone
- G'p
phosphorylation potential, the Gibbs energy change for ATP-synthesis from ADP and Pi
- G'0p
standard Gibbs energy change at specified conditions
- H+/ATP
number of protons translocated through
- ATP
synthase in synthesis of one ATP
- H+/O
protons translocated during transfer of 2 electrons from substrate to oxygen
-
specific growth rate (1/h)
- H+
transmembrane electrochemical proton potential, J/mol
- Mb
molar weight (147.6 g/mol) of bacteria with general cell formula C6.0H10.8O3.0N1.2
- pHout,in
extracellular, intracellular pH
- Pi
(intracellular) inorganic phosphate
- p
proton motive force, mV
- pH
transmembrane pH-difference
-
transmembrane electrical potential, mV
- P/O
number of ADP phosphorylated to ATP upon reduction of one O2– to H2O by two electrons transferred through the electron transfer chain
- P/O
(H+/O) × (H+/ATP)–1
- P/OF, P/ON
P/O with the two electrons donated by resp. (NADH + H+) and FADH
- q
specific rate of consumption or production (mol/g DW × h)
-
rel
+,rel
–
stringent, relaxed genotype
- R
universal gas constant, 8.36 J/(mol × degree)
- T
absolute temperature
- TPMP+
triphenylmethylphosphonium ion
- TPP+
tetraphenyl phosphonium ion
- Y
growth yield, g DW/mol
- Z
conversion constant=61.8 mV for 310 K (37 °C)
- ZpH
transmembrane proton potential or chemical potential, mV 相似文献
7.
Hiroyuki Noji Toyoki Amano Masasuke Yoshida 《Journal of bioenergetics and biomembranes》1996,28(5):451-457
Exchange-out of amide tritium from labeled -subunit of 33 complex of F0F1-ATP synthase was not accelerated by ATP, suggesting that hemagglutinin-type transition of coiled-coil structure did not occur in -subunit. Local topology of nucleotide binding site and switch II region of G-protein resemble those of F1- subunit and other proteins which catalyze ATP-triggered reactions. Probably, binding of nucleotide to F0F1-ATP synthase induces conformational change of the switch II-like region with transforming subunit structure from open to closed form and this transformation results in loss of hydrogen bonds with the subunit, thus enabling the subunit to move. 相似文献
8.
William F. Hopkins Sahba Fatherazi Bettina Peter-Riesch Barbara E. Corkey Daniel L. Cook 《The Journal of membrane biology》1992,129(3):287-295
Summary ATP-inhibited potassium channels (K(ATP)) were studied in excised, inside-out patches from cultured adult mouse pancreatic -cells and HIT cells. In the absence of ATP, ADP opened K(ATP) channels at concentrations as low as 10
m and as high as 500
m, with maximal activation between 10 and 100
m ADP in mouse -cell membrane patches. At concentrations greater than 500
m, ADP inhibited K(ATP) channels while 10 mm virtually abolished channel activity. HIT cell channels had a similar biphasic response to ADP except that more than 1 mm ADP was required for inhibition. The channel opening effect of ADP required magnesium while channel inhibition did not. Using creatine/creatine phosphate solutions with creatine phosphokinase to fix ATP and ADP concentrations, we found substantially different K(ATP)-channel activity with solutions having the same ATP/ADP ratio but different absolute total nucleotide levels. To account for ATP-ADP competition, we propose a new model of channel-nucleotide interactions with two kinds of ADP binding sites regulating the channel. One site specifically binds MgADP and increases channel opening. The other, the previously described ATP site, binds either ATP or ADP and decreases channel opening. This model very closely fits the ADP concentration-response curve and, when incorporated into a model of -cell membrane potential, increasing ADP in the 10 and 100
m range is predicted to compete very effectively with millimolar levels of ATP to hyperpolarize -cells.The results suggest that (i) K(ATP)-channel activity is not well predicted by the ATP/ADP ratio, and (ii) ADP is a plausible regulator of K(ATP) channels even if its free cytoplasmic concentration is in the 10–100
m range as suggested by biochemical studies.We would like to thank Mr. Louis Stamps for expert technical assistance and Dr. Wil Fujimoto and Ms. Jeanette Teague for generously providing HIT cells obtained from Dr. Robert Santerre at Eli Lilly. We would also like to thank Dr. Michel Vivaudou for providing the program ALEX. Support was provided by the NIH and the Department of Veterans Affairs. 相似文献
9.
A K+-selective,three-state channel from fragmented sarcoplasmic reticulum of frog leg muscle 总被引:9,自引:0,他引:9
Summary Sarcoplasmic reticulum (SR) vesicles from frog leg muscle were fused with a planar phospholipid bilayer by a method described previously for rabbit SR. As a result of the fusion, K+-selective conduction channels are inserted into the bilayer. Unlike the two-state rabbit channel, the frog channel displays three states: a nonconducting (closed) state and two conducting states and . In 0.1m K+ the single-channel conductances are 50 and 150 pS for and , respectively. The probabilities of appearearance of the three states are voltage-dependent, and transitions between the closed and states proceed through the state. Both open states follow a quantitatively identical selectivity sequence in channel conductance: K+>NH
4
+
>Rb+>Na+>Li+>Cs+. Both open states are blocked by Cs+ asymmetrically in a voltage-dependent manner. The zero-voltage dissociation constant for blocking is the same for both open states, but the voltage-dependences of the Cs+ block for the two states differ in a way suggesting that the Cs+ blocking site is located more deeply inside the membrane in the than in the state. 相似文献
10.
Butler SP O'Sickey TK Lord ST Lubon H Gwazdauskas FC Velander WH 《Transgenic research》2004,13(5):437-450
Transgenic animals secreting individual chains and assembled fibrinogen were produced to evaluate the capacity of the mammary gland for maximizing assembly, glycosylation and secretion of recombinant human fibrinogen (rhfib). Transgenes were constructed from the 4.1kbp murine Whey Acidic Protein promoter (mWAP) and the three cDNAs coding for the A, B and fibrinogen chains. Transgenic mice secreted fully assembled fibrinogen into milk at concentrations between 10 and 200 g/ml, with total secretion of subunits approaching 700 g/ml in milk. Partially purified fibrinogen was shown to form a visible and stable clot after treatment with human thrombin and factor XIII. The level of assembled fibrinogen was proportional to the lowest amount of subunit produced where both the B and chains were rate limiting. Both the B and chains were glycosylated when co-expressed and the degree of saccharide maturation was dependent on expression level, with processing preferred for chains over B chains. Also, the subunit complexes 2, A2 and the individual subunits A, B and were found as secretion products. When the B was secreted individually, the glycosylation profile of the molecule was of a mature complex saccharide indicating recognition of the molecule by the glycosylation pathway without association with other fibrinogen chains. To date secretion of B chain has been not observed in any cell type, suggesting that the secretion pathway in mammary epithelia is less restrictive than that occurring in hepatocytes and other cells previously used to study fibrinogen assembly. 相似文献
11.
Keshava Nagalakshmi Zhou Gu Spruill Michelle Ensell Mang Ong Tong-man 《Molecular and cellular biochemistry》2001,222(1-2):69-76
Occupational exposure to beryllium (Be) and Be compounds occurs in a wide range of industrial processes. A large number of workers are potentially exposed to this metal during manufacturing and processing, so there is a concern regarding the potential carcinogenic hazard of Be. Studies were performed to determine the carcinogenic potential of beryllium sulfate (BeSO4) in cultured mammalian cells. BALB/c3T3 cells were treated with varying concentrations of BeSO4 for 72 h and the transformation frequency was determined after 4 weeks of culturing. Concentrations from 50–200 g BeSO4/ml, caused a concentrationdependent increase (9–41 fold) in transformation frequency. Nontransformed BALB/c3T3 cells and cells from transformed foci induced by BeSO4 were injected into both axillary regions of nude mice. All ten Beinduced transformed cell lines injected into nude mice produced fibrosarcomas within 50 days after cell injection. No tumors were found in nude mice receiving nontransformed BALB/c3T3 cells 90 days postinjection. Gene amplification was investigated in Kras, cmyc, cfos, cjun, csis, erbB2 and p53 using differential PCR while random amplified polymorphic DNA fingerprinting was employed to detect genomic instability. Gene amplification was found in Kras and cjun, however no change in gene expression or protein level was observed in any of the genes by Western blotting. Five of the 10 transformed cell lines showed genetic instability using different random primers. In conclusion, these results indicate that BeSO4 is capable of inducing morphological cell transformation in mammalian cells and that transformed cells induced by BeSO4 are potentially tumorigenic. Also, cell transformation induced by BeSO4 may be attributed, in part, to the gene amplification of Kras and cjun and some BeSO4induced transformed cells possess neoplastic potential resulting from genomic instability. 相似文献
12.
In this paper we use a dynamical systems approach to prove the existence of a unique critical value c
* of the speed c for which the degenerate density-dependent diffusion equation u
ct
= [D(u)u
x
]
x
+ g(u) has: 1. no travelling wave solutions for 0 < c < c
*, 2. a travelling wave solution u(x, t) = (x - c
*
t) of sharp type satisfying (– ) = 1, () = 0 *; '(*–) = – c
*/D'(0), '(*+) = 0 and 3. a continuum of travelling wave solutions of monotone decreasing front type for each c > c
*. These fronts satisfy the boundary conditions (– ) = 1, '(– ) = (+ ) = '(+ ) = 0. We illustrate our analytical results with some numerical solutions. 相似文献
13.
Atul K. Johri Meenakshi Dua Dipika Tuteja Renu Saxena D.M. Saxena Rup Lal 《Biotechnology letters》1998,20(9):885-887
Sphingomonas paucimobilis degrades aerobically , , and -hexachlorocyclohexane. With -HCH, complete degradation occurred after 3 days but with and , and with -HCH, 98 and 56 % degradation occurred after 12 and 8 days of incubation, respectively. Pentachlorocyclohexene was formed as the primary metabolite during the degradation of all the HCH isomers. © Rapid Science Ltd. 1998 相似文献
14.
Boel Lanne Jeana Cîopraga Jörgen Bergström Cecilia Motas Karl-Anders Karlsson 《Glycoconjugate journal》1994,11(4):292-298
The carbohydrate-binding specificity ofPseudomonas aeruginosa lectin I (PA-I) in iodinated or biotinylated form was studied. A large number of glycosphingolipids, as well as some glycoproteins and neoglycoproteins were used as ligands. Also, inhibition by free saccharides of PA-I binding to glycosphingolipids was tested. It was found that the lectin binds most strongly to terminal and nonsubstituted Gal3Gal- or Gal4Gal-structures.Abbreviations PA-I
Pseudomonas aeruginosa lectin I
- Cer
ceramide
- lactosylceramide
Gal4GlcCer
- iso globotriaosylcerami
Gal3Gal4GlcCer
- globotriaosylceramide
Gal4Gal4GlcCer
- globoside or globotetraosylceramide
GalNAc3Gal4Gal4GlcCer
- Forssman glycolipid
GalNAc3GalNAc3Gal4Gal4GlcCer
- P1 glycolipid
Gal4Gal4GlcNAc3Gal4GlcCer
- lactoneotetraosylceramide
Gal4GlcNAc3Gal4GlcCer
- B5 glycolipid
Gal3Gal4GlcNAc3Gal4GlcCer
- gangliotetraosylceramide
Gal3GalNAc4Gal4GlcCer
- GM1
Gal3GalNAc4(NeuAc3)Gal4GlcCer
- RBC
red blood cells
- BSA
bovine serum albumin
- PBS
phosphate-buffered saline
- SDS
sodium dodecyl sulfate
- TLC
thin-layer chromatography
- HPLC
high pressure liquid chromatography
- MS
mass spectrometry
- FAB
fast-atom bombardment
- EI
electron impact 相似文献
15.
The most commonly quoted mechanism of the coupling between the electrochemical proton gradient and the formation of ATP from ADP and Pi assumes that all states of the F1 portion of the ATP synthase have subunits in tight, loose, and open conformations. Models based on this assumption are inconsistent with some of the available experimental evidence. A mechanism that includes an additional subunit conformation, closed, observed in the rat liver structure overcomes these difficulties. 相似文献
16.
D. Jebram 《Helgoland Marine Research》1977,29(3):404-413
In the ascophoran bryozoanCryptosula pallasiana (Moll) many examples of regenerative growth and of abnormal zooids have been observed. Most of the different forms of monsters are caused by fusion of zooids or zooid buds respectively. Zooids may often fuse laterally but in a few cases also distally. Some monster zooids have two polypides and combined opercula caused by various degrees of fusion of the apertures. Lack of sufficient space may lead to the formation of dwarf zooids or remainder cystids. 相似文献
17.
Minimal photosynthetic catalytic F1() core complexes, containing equimolar ratios of the and subunits, were isolated from membrane-bound spinach chloroplast CF1 and Rhodospirillum rubrum chromatophore RrF1. A CF1-33 hexamer and RrF1-11 dimer, which were purified from the respective F1() complexes, exhibit lower rates and different properties from their parent F1-ATPases. Most interesting is their complete resistance to inhibition by the general F1 inhibitor azide and the specific CF1 inhibitor tentoxin. These inhibitors were earlier reported to inhibit multisite, but not unisite, catalysis in all sensitive F1-ATPases and were therefore suggested to block catalytic site cooperativity. The absence of this typical property of all F1-ATPases in the 11 dimer is consistant with the view that the dimer contains only a single catalytic site. The 33 hexamer contains however all F1 catalytic sites. Therefore the observation that CF1-33 can bind tentoxin and is stimulated by it suggests that the F1 subunit, which is required for obtaining inhibition by tentoxin as well as azide, plays an important role in the cooperative interactions between the F1-catalytic sites.Abbreviations CF0F1
chloroplast F0F1
- CF1
chloroplast F1
- CF1
chloroplast F1 subunit
- CF1
chloroplast F1 subunit
- CF1()
a complex containing equal amounts of the CF1 and subunits
- MF1
mitochondrial F1
- RrF0F1
Rhodospirillum rubrum F0F1
- RrF1
R. rubrum F1
- RrF1
R. rubrum F1 subunit
- RrF1
R. rubrum F1 subunit
- RrF1()
a complex containing equal amounts of the RrF1 and subunits
- Rubisco
Ribulose-1,5-bisphosphate carboxylase
- TF1
thermophilic bacterium PS3 F1 相似文献
18.
Peter Schopfer 《Planta》1967,72(4):297-305
Zusammenfassung Die positiven Photomorphosen Öffnung des Hypokotylhakens und Entfaltung der Kotyledonen können ganz ähnlich wie die phytochrominduzierte Anthocyansynthese und andere positive Photomorphosen durch Actinomycin D und Puromycin gehemmt werden. Man kann daraus schließen, daß diese beiden photomorphogenetischen Reaktionen des Senfkeimlings ebenfalls durch eine von P730 über eine Signalkette ausgelöste Aktivierung von potentiell aktiven Genen veranlaßt werden.
Die Arbeit wurde durch Sachbeihilfen der Deutschen Forschungsgemeinschaft und der Stiftung Volkswagenwerk (an Prof. Mohr) ermöglicht. 相似文献
The inhibition of phytochrome-mediated photomorphogenesis (positive photoresponses) by actinomycin D and puromycin in the mustard seedling (Sinapis alba L.)
Summary The many photochrome-mediated photoresponses of a seedling (Sinapis alba L., white seeded mustard) can be divided into 3 categories: positive, negative, and complex photoresponses. Positive photoresponses are those which are characterized by an initiation or a promotion of biosynthetic or growth processes (Mohr, 1966b). Phytochrome-mediated anthocyanin synthesis is the prototype of a positive photoresponse. It has been shown in previous papers (e.g. Lange and Mohr, 1965; Mohr et al., 1965) that positive photoresponses can be specifically inhibited by actinomycin D and puromycin. It has been concluded that in the case of positive photoresponses P730 (the active phytochrome) exerts its function through differential gene activation.—In the present paper it has been demonstrated that phytochrome-mediated positive photoresponses of the mustard seedling like opening of the hypocotylar hook and unfolding of the cotyledons can be inhibited by relatively low doses of actinomycin D and puromycin in very much the same way as anthocyanin synthesis or cotyledon enlargement is inhibited. It has been concluded that in these cases too the action of P730 must be attributed to an activation of potentially active genes in the manner postulated on the basis of the data on anthocyanin synthesis.
Die Arbeit wurde durch Sachbeihilfen der Deutschen Forschungsgemeinschaft und der Stiftung Volkswagenwerk (an Prof. Mohr) ermöglicht. 相似文献
19.
V. R. Reddi V. Padmaja 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1982,61(1):35-40
Summary The seven possible primary trisomics of Petunia (2 n= 14) located in the progenies of triploid, hypertriploid and hypotriploid plants were distinguished from one another and from diploid on the basis of cytological and morphological criteria. They were provisionally named as Oval, Semi, Slender, Pseudonormal, Arrow, Narrow and Giant. In three of the trisomics, the extra chromosome was identified for the first time at pachytene stage. Postpachytene studies revealed no precise relationship between the length of extra chromosome and the frequency of multiple association. 相似文献
20.
An increase in the “inhibitor-β” content of detached wheat leaves following a period of wilting 总被引:2,自引:1,他引:1
S. T. C. Wright 《Planta》1969,86(1):10-20
Summary Wheat seedlings were grown under a 14-hour photoperiod and the first leaves excised at the end of the eighth dark period. The effect of treatments causing wilting on the inhibitor- content of such leaves was studied.When leaves were rapidly wilted (i.e. to a 6% fresh weight loss) and extracted immediately, the amount of inhibitor- per leaf was found to be the same as in fresh turgid leaves. However, when the leaves were maintained in a wilted condition in darkness for a period of 110 minutes, there was a marked increase in inhibitor- content.The greater the degree of wilting (i.e. up to about a 9% loss in fresh weight) the greater the eventual inhibitor- content. Moreover, the increment in inhibitor- was shown to be temperature dependent.The time lapse requirement and the temperature dependency of the inhibitor- formation suggest an enzymic conversion from a precursor.If a similar phenomenon occurs during the wilting of intact plants then the increase in this growth inhibitor might play a role in some of the physiological changes which accompany water stress. 相似文献