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31.
A high level of binding of [3H]methyltrienolone (R1881 = 17beta-hydroxy-17alpha-methyl-estra-4, 9, 11-trien-3-one) was found in cytosol prepared from adrenals of castrated male rats. Binding of [3H]R1881 was of high affinity (DK = 6.2 nM) and highly specific for androgens. The [3H]R1881 complex migrates at 7-9S on sucrose gradients in low ionic strength buffer and at 4-5S in buffer containing 0.4M KC1. All binding studies have been performed in parallel with rat ventral prostate and adrenal cytosol. The present data suggest the presence of an androgen binding component in rat adrenal tissue. 相似文献
32.
Harvey R. Herschman Dennis S. Passovoy Rebecca M. Pruss Aharon Aharonov 《Journal of cellular biochemistry》1978,8(3):263-268
The growth-promoting activities of fetal bovine serum, cortisol, phorbol myristate acetate, prostaglandin F2α, insulin, epidermal growth factor, and fibroblast growth factor were evaluated on four murine embryo cell lines (Swiss 3T3, Balb 3T3, M2, and C3H10T1/2). Each cell had an unique response spectrum to this collection of reported mitogens. Phorbol myristate acetate and prostaglandin F2α were active only on selected cell lines; cortisol was inactive on all four lines. Serum, epidermal growth factor, and fibroblast growth factor were able to stimulate cell division in all four lines, albeit to varying degrees for the different target cells. 相似文献
33.
We investigated the influence of CO2/HCO3
–-depletion and of the presence of acetate and formate on the in vivo photosynthetic electron transport in the two green algae Chlamydobotrys stellata and Chlamydomonas reinhardtii by means of thermoluminescence technique and mathematical glow curve analysis. The main effects of the removal of CO2 from the algal cultures was: (1) A shift of the glow curve peak position to lower temperatures resulting from a decrease of the B band and an increase of the Q band. (2) Treatment of CO2-deficient Chl. stellata with DCMU yielded two thermoluminescence bands in the Q band region peaking at around +12°C and +5°C; in case of Chl. reinhardtii DCMU treatment induced only one band with an emission maximum at +5°C. The presence of acetate or formate in CO2-depleted algal cultures lowered the intensities of all of the individual TL bands but that of a HT band (TL+37). The effects of CO2-depletion and of the presence of anions were fully reversible.Abbreviations DCMU
3-(3,4)-dichlorophenyl-1,1-dimethylurea
- HT band
high temperature TL band
- P680
reaction center chlorophyll of PS II
- QA and QB
primary and secondary quinone acceptors of PS II, respectively
- PS II
Photosystem II
- S2/3
redox states of the oxygen evolving complex of PS II
- TL
thermoluminescence 相似文献
34.
Vertical profiles were measured in soil cores taken from flooded rice fields in the Po valley during July and August 1990.
Methane concentrations generally increased with depth and reached maximum values of 150–500 μM in 5–13 cm depth. However,
the shape of the profiles was very different when studying different soil cores. The CH4 content of gas bubbles showed a similar variability which apparently was due to spatial rather than temporal inhomogeneities.
Similar inhomogeneities were observed in the vertical profiles of acetate, propionate, lactate, and formate which showed maximum
values of 1500, 66, 135, and 153, μM, respectively. However, maxima and minima of the vertical profiles of the different substates
usually coincided in one particular soil core. Large inhomogeneities in the vertical profiles were also observed for the rates
of total CH4 production, however, the percentage contribution of H2/CO2 to CH4 production was relatively homogeneous at 24 ± 7% (SD). Similarly, the H2 content of gas bubbles was relatively constant at 93.3 ± 9.6 ppmv when randomly sampled in the rice field at different times
of the day. A small contribution (6%) of H2/CO2 to acetate production was also observed. Vertical profiles of the respiratory index (RI) for [2-14C] acetate showed that acetate was predominantly degraded by methanogenesis in 5–11 cm depth, but by respiration in the surface
soil (3 cm depth) and in soil layers below 13–16 cm depth which coincided with a transition of the colour (grey to reddish)
and the physical characteristics (porosity, density) of the soil. The observations indicate that the microbial community which
degrades organic matter to CH4 is in itself relatively homogenous, but operates at highly variable rates within the soil structure.
Author for correspondence 相似文献
35.
C. Tonini G. Cassani P. Piccardi S. Maini P.L. Castellari E. Pasqualini 《Journal of insect physiology》1982,28(5):443-446
Female-tip washings of the leafroller moth, Pandemis cerasana, were found to contain (E)-11-tetradecenyl acetate, (Z)-11-tetradecenyl acetate, (E)-11-tetradecenol, (Z)-11-tetradecenol and tetradecyl acetate, based on chemical analysis and electroantennogram tests. The relative amounts of these compounds in the gland were ca. 64:21:10:3:2 in the order named. Only (E)-11 and (Z)-11-tetradecenyl acetate were required for attraction of males to trap dispensed in the ratio 3:1, respectively. 相似文献
36.
Investigation of the North American species Psilostrophe villosa afforded, in addition to known compounds, five new sesquiterpene lactones, which all turn out to be modified pseudoguaianolides, most of them closely related to hymenolide. However, one of the lactones is a new type of nor-pseudoguaianolide. Furthermore a new monoacetylated borneol-β-D-glucoside is present. The chemotaxonomic situation is discussed briefly. 相似文献
37.
Biological activity of the antitumor protein neocarzinostatin coupled to a monoclonal antibody by N-succinimidyl 3-(2-pyridyldithio)-propionate 总被引:6,自引:0,他引:6
Gundram Jung Wolfgang Köhnlein Gerd Lüders 《Biochemical and biophysical research communications》1981,101(2):599-606
The chromophore free apoprotein of neocarzinostatin was coupled to monoclonal IgG1 antibody using N-Succinimidyl 3-(2-pyridyldithio)-propionate as heterobifunctional reagent. After coupling active chromophore was reassociated with the apoprotein. We present here experimental evidence that the hybrid protein retains biological activity as measured by the degradation of T2-DNA and bacteriostatic action. 相似文献
38.
39.
Human placental microsomes were incubated with [3H]benzo[a]pyrene (BP) and Salmon sperm DNA and the resulting metabolite-nucleoside complexes resolved by Sephadex LH-20 chromatography. The metabolite pattern was analyzed by high-pressure liquid chromatography (HPLC). The incubates were also co-chromatographed with extracts obtained from incubates with rat liver microsomes and [14C]BP. Phenols, quinones and 7,8-dihydrodiol were detected in the placental incubates. Both 9,10- and 4,5-dihydrodiols were very low as compared with control rat liver samples. Placental microsomes catalyzed the binding of BP metabolites to DNA in vitro, giving rise to two main complexes which co-chromatographed with rat liver-produced peaks attributable to 7,8-diol-9,10-epoxide and 7,8-oxide and/or quinones when metabolized further. The nucleoside metabolite peaks attributable to 4,5-oxide and 9-phenol-4,5-oxide were lacking when compared with the binding pattern catalyzed by rat liver. Both the total binding and specific metabolite-nucleoside adducts in the placenta correlated with fluorometrically measured aryl hydrocarbon hydroxylase (AHH) activity and with the amount of dihydrodiol formed. The results demonstrate that both the metabolite pattern and the nucleoside-metabolite complexes formed by the placental microsomes in vitro differed greatly from those produced by rat liver microsomes. These studies also suggest that it is not possible to predict specific patterns of DNA binding from AHH measurements or even from BP metabolite patterns, especially when comparing different tissues and species. 相似文献
40.
A collagenase, active against native helical collagen, was initially found in the explant medium of bovine dental pulp. In contrast to the collagenases from other oral tissues, all the pulp enzyme released was in a latent form which was activated by trypsin treatment, 4-aminophenylmercuric acetate, and some chaotropic agents. The activated enzyme was inhibited by low concentrations of EDTA and calf serum. The molecular weight of activated enzyme was tentatively estimated at 45,000 daltons by gel filtration. The enzyme attacked undenatured collagen in solution at 20°C producing characteristic products and . 相似文献