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1.
Zofia Maskos Karl Fisher Morten Sørlie William E. Newton Brian J. Hales 《Journal of biological inorganic chemistry》2005,10(4):394-406
The resting state of wild-type nitrogenase MoFe protein exhibits an S=3/2 electron paramagnetic resonance (EPR) signal originating from the FeMo cofactor, the enzymes active site. When nitrogenase turns over under CO, this signal disappears and one (sometimes two) of three new EPR signals, which also arise from the FeMo cofactor, appears, depending on the CO concentration. The appearance and properties of these CO-inducible EPR signals, which were also generated with variant MoFe proteins (R96Q, R96K, Q191K, R359K, R96K/R359K, R277C, R277H, and nifV) that are impacted around the FeMo cofactor, have been investigated. No new CO-induced EPR signals arise from any variant, suggesting that no new CO-binding sites are produced by the substitutions. All variant proteins, except R277H, produce the lo-CO signal; all, except Q191K, produce the hi(5)-CO signal; but only two (R96Q and nifV) exhibit the hi-CO signal. FeMo cofactors environment clearly dictates which CO-induced EPR signals are generated; however, none of these EPR signals correlate with CO inhibition of H2 evolution observed with some of these variants. CO inhibition of H2 evolution is, therefore, due to CO binding to a different site(s) from those responsible for the CO-induced EPR signals. Some resting-state variants have overlapping S=3/2 EPR signals, whose intensities simultaneously decrease under turnover conditions, indicating that all FeMo cofactor conformations are catalytically active. Moreover, these variants produce a similar number of hi(5)-CO signals after turnover under CO to the number of resting-state S=3/2 signals. The FeMo cofactor associated with the hi(5)-CO signal likely contains two bridging CO molecules. 相似文献
2.
American ginseng, Panax quinquefolius L., is one of the most heavily traded medicinal plants in North America. The effect of harvest on genetic diversity in ginseng was measured with a single generation culling simulation program. Culling scenarios included random harvest at varying levels, legal limit random harvest and legal limit mature plant harvest. The legal limit was determined by the proportion of legally harvestable plants per population (% mature plants per population). Random harvest at varying levels resulted in significant loss of genetic diversity, especially allelic richness. Relative to initial levels, average within-population genetic diversity (H
e) was significantly lower when plants were culled randomly at the legal limit (Mann–Whitney U=430, p<0.001) or when only mature plants were culled (Mann–Whitney U=394, p<0.01). Within-population genetic diversity was significantly higher with legal limit mature plant harvest (H
e=0.068) than when plants were culled randomly at the legal limit (H
e=0.064; U=202, p<0.01). Based on these simulations of harvest over one generation, we recommend that harvesting fewer than the proportion of mature plants could reduce the negative genetic effects of harvest on ginseng populations. 相似文献
3.
The thermodynamics of the methylenetetrahydrofolate reduction to 5-methyltetrahydrofolate was studied with the methylenetetrahydrofolate reductase purified from the homoacetogenic bacterium Peptostreptococcus productus. The equilibrium constants were determined for the forward and backward reactions of methylenetetrahydrofolate reduction with NADH or acetylpyridine adenine dinucleotide (APADH), respectively, as the electron donors. From the equilibrium constants and the known standard redox potentials at pH 7 (E
o
) of the couples NAD+/NADH or APAD+/APADH the E
o
of the couple methylene-/methyltetrahydrofolate was determined to be about-200mV. This value is different from values reported before for this couple. The implications for the mechanism of energy conservation of homoacetogens is discussed.Abbreviations FH4
tetrahydrofolate
- CH2=FH4
5,10-methylenetrahydrofolate
- CH3-FH4
5-methyltetrahydrofolate
-
K
eq
equilibrium constant
-
G
o
Gibb's free energy change under standard conditions (all concentrations of reactants = 1 M)
-
G
o
G
o at pH 7 ([H+]=10-7 M)
-
E
o
standard redox potential
-
G
o
standard redox potential difference of two reactants
-
E
o
E
o at pH 7
-
R
gas constant
-
F
Faraday constant
- APAD
acetylpyridine adenine dinucleotide (NAD+-analogue) 相似文献
4.
Jacques Raymond Brahim Mimouni Jean-Louis Azanza 《Plant Systematics and Evolution》1994,193(1-4):69-79
The seed storage globulins from sixHelianthus and four hybrids were studied using mono and bidimensional gel SDS electrophoresis (+ 2 mercaptoethanol). The polypeptide composition of each subunit was determined. Different pairs are specifically expressed according to the species studied. Three typical patterns were discriminated. All the studied species exhibit five subunits: two of them are expressed in all the species (11 and 22). The subunit corresponding to the 11 pair is present inH. petiolaris and in the three populations ofH. annuus studied. The 2b2 pair is common toH. annuus andH. argophyllus. H. petiolaris presents two specific 2a2 and 44 pairs andH. annuus a specific 33 pair. InH. argophyllus 11 33 or 44 are never observed but are replaced by 13 and 31 pairs. Some globulins, poorly represented, are of forms but present chains of higher molecular weights (in the range 54–56 kDa). Expressing variations in the banding patterns between these species by the use of a similarity index reveals complete identity between the three populations ofH. annuus. Identity between the twoH. petiolaris studied is also observed.H. annuus andH. argophyllus appear to be closer to each other thanH. petiolaris concerning the seed storage globulins. 相似文献
5.
Göran Andersson Bertil Lindblom Leif Andersson Jack Gorski Bernard Mach Lars Rask 《Immunogenetics》1988,28(1):1-5
In most individuals two HLA-DR
genes are expressed from each chromosome. One of these genes encodes one of the classical DR specificities, while the other encodes either of the supertypic DRw52/DRw53 specificities. In addition to these genes usually one or two DR
pseudogenes are present. In contrast, the DRw8 chromosomal region only contains a single DR
gene. To determine the relationship of this single gene to the multiple DR
genes of other DR specificities, comparisons of Southern genomic blots were carried out. In this analysis genomic clones for each individual DR
chain locus were included. The DR
w8 gene was indistinguishable from the DR
III gene of DR3 cells (encoding DRw52), suggesting that it is closely related to the latter gene. The functional implications of this finding are discussed. 相似文献
6.
The Ca2+ channel 1B subunit is a pore-forming component capable of generating N-type Ca2+ channel activity. Although N-type Ca2+ channel plays a role in a variety of neuronal functions, 1B-deficient mice exhibit normal life span without apparent abnormalities of behavior, histology or plasma norepinephrine level, presumably owing to compensation by some other Ca2+ channel 1 or subunit. In this study, we studied the levels of 1A, 1C, 1D, 1E, 1, 2, 3 and 4 mRNAs in adrenal gland of 1B-deficient mice. The 1A mRNA in homozygous mice was expressed at higher level than in wild or heterozygous mice, but no difference in the expression levels of 1C, 1D, 1E, 1, 2, 3 and 4 was found among wild, heterozygous and homozygous mice. The protein level of 1A in homozygous mice was also expressed at higher level than in wild or heterozygous mice. To examine whether increased expression is induced by cis-regulatory element within 5-upstream region of 1A gene, we examined lacZ expression in 1B-deficient × 1A6.3-lacZ mice (carrying a 6.3-kb 5-upstream fragment of 1A gene fused to E. coli lacZ reporter gene), which express lacZ in medullar chromaffin cells, but not in cortex. The levels of lacZ expression in homozygous 1B-deficient × 1A6.3-lacZ mice were higher than in wild or heterozygous mice. Therefore, a possible explanation of the normal behavior and plasma norepinephrine level of 1B-deficient mice is that compensation by 1A subunit occurs and that 6.3-kb 5-upstream region of 1A gene contains enhancer cis-element(s) for compensation in adrenal medulla chromaffin cells. (Mol Cell Biochem 271: 91–99, 2005) 相似文献
7.
François Chaumont Marcio de Castro Silva Filho Didier Thomas Serge Leterme Marc Boutry 《Plant molecular biology》1994,24(4):631-641
The mitochondrial F1-ATPase subunit (ATPase-) of Nicotiana plumbaginifolia is nucleus-encoded as a precursor containing an NH2-terminal extension. By sequencing the mature N. tabacum ATPase-, we determined the length of the presequence, viz. 54 residues. To define the essential regions of this presequence, we produced a series of 3 deletions in the sequence coding for the 90 NH2-terminal residues of ATPase-. The truncated sequences were fused with the chloramphenicol acetyl transferase (cat) and -glucuronidase (gus) genes and introduced into tobacco plants. From the observed distribution of CAT and GUS activity in the plant cells, we conclude that the first 23 amino-acid residues of ATPase- remain capable of specifically targeting reporter proteins into mitochondria. Immunodetection in transgenic plants and in vitro import experiments with various CAT fusion proteins show that the precursors are processed at the expected cleavage site but also at a cryptic site located in the linker region between the presequence and the first methionine of native CAT. 相似文献
8.
Jeremy R. Mason 《Archives of microbiology》1994,162(1-2):57-62
The oxidation of catechol, an intermediate in benzene catabolism, was studied using transient variations in dissolved oxygen tension (DOT) when a succinate limited steady state culture of Pseudomonas putida ML2 was perturbed with a pulse of another substrate. A model was developed and tested for the effect of fluctuations in oxidizing enzyme activity on DOT. It was found that the rate of induction of catechol oxidizing enzymes was independent of dilution rate up to a relative growth rate /max of 0.75. Only at higher dilution rates was catabolite repression observed.Abbreviations
DOT
dissolved oxygen tension
-
K
L
a
gas transfer coefficient
-
specific growth rate
- max
maximum specific growth rate
- Ks
substrate saturation constant 相似文献
9.
Defining patch contribution in source-sink metapopulations: the importance of including dispersal and its relevance to marine systems 总被引:1,自引:1,他引:0
In metapopulations, individual patch contribution (source or sink) is typically calculated as a patch growth rate (the intrinsic lambda, I) dependent only upon local demographics. We demonstrate that when dispersal is explicitly included in the model, the growth rates for all patches calculated in an analogous manner (the observed lambda, O) equilibrate to the overall metapopulation growth rate and thus no longer serve as a useful reflection of the demographic and dispersive characteristics of a given patch. In these situations we suggest an alternative method of estimating patch contribution (the contribution lambda, C) in which a patch is decremented for losses that occur within it and credited for gains that occur anywhere in the metapopulation because of it. We compare values of I, O, and C for individual patches in discrete-time density-independent metapopulation models of two organisms with very different life histories, mayflies with adult dispersal, and reef fish with larval dispersal. Results confirm that when dispersal is included only C clearly indicates the contribution of a particular patch. I–C comparisons indicate that inclusion of dispersal in the mayfly model was only important if connectivity patterns were random or directional. In the reef fish model, however, results were very different when dispersal was included and there were many cases of patches being misidentified (e.g., as a source when it was really a sink) depending upon the metric used (I or C). Our results demonstrate the importance of including dispersal in metapopulation models when considering the contribution of individual patches. 相似文献
10.
Heidrun Lorenzl Fred Bernd Oppermann Bernhard Schmidt Alexander Steinbüchel 《Antonie van Leeuwenhoek》1993,64(1):9-15
InClostridium magnum strain Wo Bd P1 the formation of the enzyme components of the acetoin dehydrogenase enzyme system E1 (acetoin:2,6-dichlorophenolindophenol oxidoreductase Ao:DCPIP OR), E2 (dihydrolipoamide acetyltransferase DHLTA) and E3 (dihydrolipoamide dehydrogenase DHLDH) were induced during growth on acetoin. Ao:DCPIP OR was purified from acetoin-grown cells in two steps by chromatography on DEAE-Sephacel and on Mono Q HR. Native Ao:DCPIP OR exhibited a Mr of 138,000; it consisted of two different subunits of Mr 38,500 and Mr 34,000, and it occurred most probably in a tetrameric 22 structure. The N-terminal amino acid sequences of the - and -subunits revealed homologies to the N-termini of the corresponding subunits of Ao:DCPIP OR fromPelobacter carbinolicus and fromAlcaligenes eutrophus; furthermore, the N-terminus of the -subunit exhibited homologies to the N-termini of -subunits from different 2-oxo acid dehydrogenases.Abbreviations Ao:DCPIP OR
acetoin:2,6-dichlorophenolindophenol oxidoreductase
- DHLDH
dihydrolipoamide dehydrogenase
- DHLTA
dihydrolipoamide acetyltransferase
- HETPP
hydroxyethyl thiamine pyrophosphate 相似文献
11.
Über den Einfluß von Nahrung und Substratsalinität auf Verhalten,Fortpflanzung und Wasserhaushalt von Enchytraeus albidus Henle (Oligochaeta) 总被引:1,自引:0,他引:1
Christine Schöne 《Oecologia》1971,6(3):254-266
Zusammenfassung
Enchytraeus albidus aus dem Anwurf mariner Algen an der Kieler Förde (Ostsee) erträgt als Nahrung die folgenden dort vorkommenden Pflanzen (Reihenfolge mit abnehmender Verträglichkeit): Fucus — Grünalgen —Seegras (Zostera) — Rotalgen (Delesseria). Diese Reihenfolge gilt für Nahrungsaufnahme, Fortpflanzungsrate und Überlebensdauer.Mit zunehmender Fäulnis des Nahrungssubstrates steigt die Zahl der Tiere, die aus ihm fliehen. Ihre Anzahl wird außerdem bestimmt durch den Salzgehalt des Substrates: Von 15–45 ist sie proportional der Substratsalinität. Bei 60 ist die Aktivität der Tiere bereits stark eingeschränkt.Bei Fucus-Nahrung ertragen auf Sand gehaltene Tiere eine Salinität von 60–70 länger als 4 Wochen, auf Filtrierpapier dagegen nur 50 für durchschnittlich 1 Woche. Die obere Fortpflanzungsgrenze liegt bei 40 Salzgehalt im Substrat. Bei 5 werden die meisten Kokons abgelegt. Die Sterblichkeit im Kokon ist bei 15 am geringsten. Auf den Substratsalinitäten 0–15 ist die Entwicklungsdauer im Kokon signifikant kürzer als auf Substraten von 30 und 40.
Enchytraeus hat sich als Rückwanderer zum Meer mit einer sekundär erweiterten Poikilosmotie an den neuen Lebensraum angepaßt. Er kann eine Binnenkonzentration entsprechend etwa 72 längere Zeit ertragen. Auf niedrigen Salzgehalten besitzt er eine ausgeprägte Hypertonieregulation.
Summary Enchytraeus albidus was fed with Fucus, green algae, Zostera marina and Delesseria. Judging from absorption of food, rate of reproduction and duration of life, the animals preferred the plants in the sequence given above.As the putrefaction of a Fucus substrate advances, more and more enchytraeids leave it. A changing salinity of the substrate also influences the number of emigrating worms, increasing it from 15–45, but decreasing it towards 60. Fed with Fucus E. albidus tolerates a salinity of 60–70 on sand for more than 4 weeks, on filter paper only 50 for about one week.Reproduction is possible at salinities up to 40. Cocoon production is most frequent at 5. The mortality of young worms within the cocoons is lowest at 15. The incubation period is significantly shorter at salinities of 0–15 than at 30 and 40.As a terrestrial immigrant to the seashore Enchytraeus albidus secondarily enlarged its range of poikilosmosis, tolerating a concentration of 72 in its coelomic fluid for some time. At low salinities it maintains a remarkable degree of hyperosmosis.相似文献
12.
Natural abundance of 15N ( 15N) of leaves harvested from tropical plants in Brazil and Thailand was analyzed. The 15N values of non-N2-fixing trees in Brazil were +4.5±1.9, which is lower than those of soil nitrogen (+8.0±2.2). In contrast, mimosa and kudzu had very low 15N values (–1.4+0.5). The 15N values of Panicum maximum and leguminous trees, except Leucaena leucocephala, were similar to those of non-N2-fixing trees, suggesting that the contribution of fixed N in these plants is negligible. The 15N values of non-N2-fixing trees in Thailand were +4.9±2.0. Leucaena leucocephala, Sesbania grandiflora, Casuarina spp. and Cycas spp. had low 15N values, close to the value of atmospheric N2 (0), pointing to a major contribution of N2 fixation in these plants. Cassia spp. and Tamarindus indica had high 15N values, which confirms that these species are non-nodulating legumes. The 15N values of Acacia spp. and Gliricidia sepium and other potentially nodulating tree legumes were, on average, slightly lower than those of non-N2-fixing trees, indicating a small contribution of N2 fixation in these legumes. 相似文献
13.
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
14.
L. Goldman 《European biophysics journal : EBJ》1989,16(6):321-325
The time constant of the process producing the delay in Na inactivation development as determined by the two pulse method (delay) was extracted and compared to that of the slowest Na activation process 3 for the I
Na during the conditioning pulse of that same determination. delay and two pulse inactivation c values were computer generated using a nonlinear least squares algorithm. h and single pulse inactivation h values were independently generated for each determination also with the aid of the computer using the same non-linear least squares algorithm. In one determination at 2 mV, c was 4.68 and delay 0.494 ms while h was 4.70 and 3 0.491 ms for a c/h of 0.996 and a delay/3 of 1.006. Mean delay/3 from five determinations in four axons, both Cs and K perfused, and spanning a potential range of-27 to 2mV was 1.068. The precursor process to inactivation is channel opening. Some fraction of channels presumably inactivate via another route where prior channel opening is not required. 相似文献
15.
Changes of photosynthetic parameters in cucumber leaves under Cu, Cd, and Pb stress 总被引:10,自引:3,他引:7
The effects of Cu, Cd, and Pb toxicity on photosynthesis in cucumber leaves (Cucumis sativus L.) were studied by the measurements of gas exchange characteristics, chlorophyll (Chl) fluorescence parameters, and Chl content. Concentrations of metals in sequence of 20 M Cu, 20 and 50 M Cd, and 1 000 M Pb decreased the plant dry mass to 50–60 % after 10 d of treatment whereas 50 M of Cu decreased it to 30 %. The content of Cd in leaves of plants treated with 50 M Cd was three times higher than the contents of Cu and Pb after plant treatment with 50 M Cu or 1 000 M Pb. Hence Cd was transported to leaves much better than Cu and Pb. Nevertheless, the net photosynthetic rate and stomatal conductance in leaves treated with 50 M Cu or Cd were similarly reduced. Thus, Cu was more toxic than Cd and Pb for photosynthesis in cucumber leaves. None of the investigated metals decreased internal CO2 concentrations. Also the effect of metals on potential efficiency of photosystem 2, PS2 (Fv/Fm) was negligible. The metal dependent reduction of PS2 quantum efficiency (PS2) after plant adaptation in actinic irradiation was more noticeable. This could imply that reduced demand for ATP and NADPH in a dark phase of photosynthesis caused a down-regulation of PS2 photochemistry. Furthermore, in leaves of metal-treated plants the decrease in water percentage as well as lower contents of Chl and Fe were observed. Thus photosynthesis is not the main limiting factor for cucumber growth under Cu, Cd, or Pb stress.This revised version was published online in March 2005 with corrections to the page numbers. 相似文献
16.
1. Opioid (, , ) and cannabinoid (CB1, CB2) receptors are coupled mainly toGi/Go GTP-binding proteins. The goal of the present study was to determine whether different subtypes of opioid and cannabinoid receptors, when coexpressed in the same cell, share a common reservoir, or utilize different pools, of G proteins.2. The stimulation of [35S]GTPS binding by selective opioid and cannabinoid agonists was tested in transiently transfected COS-7 cells, as well as in neuroblastoma cell lines. In COS-7 cells, cotransfection of - and -opioid receptors led to stimulation of [35S]GTPS binding by either -selective (DAMGO) or -selective (DPDPE) agonists. The combined effect of the two agonists was similar to the effect of either DAMGO or DPDPE alone, suggesting the activation of a common G-protein reservoir by the two receptor subtypes.3. The same phenomenon was observed when COS-7 cells were cotransfected with CB1 cannabinoid receptors and either - or -opioid receptors.4. On the other hand, in N18TG2 neuroblastoma cells, which endogenously coexpress CB1 and -opioid receptors, as well as in SK-N-SH neuroblastoma cells, which coexpress - and -opioid receptors, the combined effects of the various agonists (the selective cannabinoid DALN and the selective opioids DPDPE and DAMGO) were additive, implying the activation of different pools of G proteins by each receptorsubtype.5. These results suggest a fundamental difference between native and artificially transfected cells regarding the compartmentalization of receptors and GTP-binding proteins. 相似文献
17.
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
18.
Summary A new PI Q0 variant (PI Q0riedenburg) is described; it is caused by a complete deletion of the 1-antitrypsin (1AT) gene. The deletion gives rise to four new restriction fragment length polymorphisms (RFLPs) detected with a genomic probe of the 5 region of the gene. Analysis of the RFLPs indicates that the deletion starts immediately upstream of exon Ic. The deletion extends into the 3 flanking region of the gene but does not include the 1AT-related gene (the PIL gene), which is located 12 kb downstream of the 1AT gene. 相似文献
19.
Anna Marina Liberati Michael Horisberger Monica Schippa Francesco Di Clemente Marco Fizzotti Stefano Filippo Maria Grazia Proietti Sergio Arzano Paolo Berruto Lucia Palmisano Saverio Cinieri 《Cancer immunology, immunotherapy : CII》1991,34(2):115-122
Summary Ten hairy-cell leukemia patients were treated with interferon (IFN-) at a dose rate of 2 × 106 IU/m2 × 5 days for 4 weeks (induction therapy) and, thereafter, at the same dose three times a week for 11 months (maintenance therapy). The effect of this treatment on serum neopterin, 2-microglobulin, (2–5)oligoadenylate [(2–5)A
n
] levels, intracellular (2–5)A
n
values and human Mx protein synthesis was analysed. There were significant rises in serum neopterin and (2–5)A
n
levels during both induction and maintenance, whereas 2-microglobulin levels rose only during induction. Rises in intracellular (2–5)A
n
were documented mainly during induction, but they were not significantly higher than pretherapy values. IFN provoked an increase in human Mx protein synthesis over the entire induction — maintenance period, but was only significantly higher than baseline during induction. All markers proved useful for monitoring the effects of IFN dose schedules, but were not predictive of clinical outcome. Natural killer activity and IFN production, which were initially defective, followed a different trend from that of the other factors studied, in that increases were documented only late in the course of therapy when the disease was already in remission. 相似文献
20.
Takatani M Nakama T Kubo K Manabe S Nakahara Y Ito Y Nakahara Y 《Glycoconjugate journal》2000,17(6):361-375
As part of a program to explore the structural requirement of N-glycans in the carbohydrate-mediated biological interactions, N-linked pentasaccharide core structure was stereochemically modified in terms of glycosidic linkage. Three isomers, -D-Man-(13)-[-D-Man-(16)]--D-Man-(14)--D-GlcNAc-(14)--D-GlcNAc-L-Asn, -D-Man-(13)-[-D-Man-(16)]--D-Man-(14)--D-GlcNAc-(14)--D-GlcNAc-L-Asn, and -D-Man-(13)-[-D-man-(16)]--D-Man-(14)--D-GlcNAc-(14)--D-GlcNAc-L-Asn, were synthesized. Synthesis of the pentasaccharide with natural linkage is also described. 相似文献