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During 5-h culture in the presence of radioactive glucose, PGE-2 (10 micrograms/ml) significantly inhibited incorporation of glucose into the acid-soluble glycogen pool. PGE-2 at 1 and 10 micrograms/ml and PGF-2 alpha at 1 microgram but not 10 micrograms/ml stimulated incorporation of glucose into non-glycogen macromolecules during culture. However, the utilization of acid-soluble glycogen and other biochemical pools was not affected by the presence of PGs in the medium during 24-h chase culture of pulse-labelled embryos. Carbon dioxide production was significantly suppressed in the presence of PGs but accumulation of lactate was not affected. The results indicate that PGE-2 and PGF-2 alpha, in physiological concentrations, directly influence the metabolism of glucose by preimplantation embryos. 相似文献
3.
Flowering in Wolffia microscopica, a short-day plant, couldbe induced with salicylic acid (SA), under long days. Aspirin,benzoic acid and salicylaldoxime were also effective for inductionof flowering in this duckweed. Amonsgt these, SA is the mosteffective compound, as it could induce flowering even at 107M. Flowering was further enhanced when Wolffia fronds were subjectedto short days, in the presence of SA. However, SA neither showedany effect on flowering ofW. microscopica in the absence ofEDTA in the nutrient medium, nor could it, by itself, supporteven the vegetative growth. The probable mechanism of actionof SA has also been discussed. It appears that the effect cannotbe due simply to chelation of metal ions and perhaps the salicylmoiety itself exerts a specific effect. (Received March 15, 1983; Accepted May 6, 1983) 相似文献
4.
Rathi R Kadian SK Khurana B Grover YP Gulati BR 《Indian journal of experimental biology》2007,45(2):212-216
With a view to use mice as an experimental model for studying immune response to bovine rotavirus (BRV), the kinetics of humoral and cellular immune responses to BRV in mice were evaluated by immunizing through intraperitoneal and oral route with UK strain of BRV. Following immunization with BRV, anti-rotavirus antibodies was developed in mice. The mean log antibody titres as measured by ELISA in mice immunized by intraperitoneal route were significantly higher than those immunized by oral route. Significant cellular immune response was observed in BRV-immunized mice on stimulation with BRV antigen, as measured by lymphocyte proliferation assay. The thymidine uptake by splenic and mesenteric lymph-node cells of intraperitoneally immunized mice on stimulation with BRV was 21328 +/- 1225 and 739 +/- 55 CPM, respectively. The splenic cells showed significantly higher stimulation (stimulation index 12.98) as compared to those of mesenteric cells (stimulation index 1.57). Foot pad inoculation test showed maximum virus-specific delayed type hypersensitivity reaction at 24 hr post-challenge following primary immunization and at 18 hr post-challenge following secondary immunization. The results indicate that BRV immunization by intraperitoneal route generates more efficient immune response in mice than by oral route and this route may be used for immune response studies involving BRV infection. 相似文献
5.
Reversible thermal denaturation of human FGF-1 induced by low concentrations of guanidine hydrochloride. 下载免费PDF全文
Human acidic fibroblast growth factor (FGF-1) is a powerful mitogen and angiogenic factor with an apparent melting temperature (Tm) in the physiological range. FGF-1 is an example of a protein that is regulated, in part, by stability-based mechanisms. For example, the low Tm of FGF-1 has been postulated to play an important role in the unusual endoplasmic reticulum-independent secretion of this growth factor. Despite the close relationship between function and stability, accurate thermodynamic parameters of unfolding for FGF-1 have been unavailable, presumably due to effects of irreversible thermal denaturation. Here we report the determination of thermodynamic parameters of unfolding (DeltaH, DeltaG, and DeltaCp) for FGF-1 using differential scanning calorimetry (DSC). The thermal denaturation is demonstrated to be two-state and reversible upon the addition of low concentrations of added guanidine hydrochloride (GuHCl). DeltaG values from the DSC studies are in excellent agreement with values from isothermal GuHCl denaturation monitored by fluorescence and circular dichroism (CD) spectroscopy. Furthermore, the results indicate that irreversible denaturation is closely associated with the formation of an unfolding intermediate. GuHCl appears to promote reversible two-state denaturation by initially preventing aggregation of this unfolding intermediate, and at subsequently higher concentrations, by preventing formation of the intermediate. 相似文献
6.
Singh S Kumar V Singh P Thakur S Banerjee BD Rautela RS Grover SS Rawat DS Pasha ST Jain SK Rai A 《Mutation research》2011,725(1-2):36-42
GSTM1, T1 and P1 are important enzymes of glutathione S-transferases (GSTs), involved in the metabolism of many endogenous and exogenous compounds. Individual genetic variation in these metabolizing enzymes may influence the metabolism of their substrates. The present study was designed to determine the genotoxic effects using DNA damage and its association with GSTM1, GSTT1, and GSTP1 (Ile105Val) genetic polymorphisms in workers occupationally exposed to organophosphate pesticides (OPs). We examined 230 subjects including 115 workers occupationally exposed to OPs and an equal number of normal healthy controls. The DNA damage was evaluated using the alkaline comet assay and genotyping was done using individual PCR or PCR-RFLP. Significantly higher DNA tail moment (TM) was observed in workers as compared to control subjects (14.41 ± 2.25 vs. 6.36 ± 1.41 tail % DNA, p<0.001). The results revealed significantly higher DNA TM in workers with GSTM1 null genotype than those with GSTM1 positive (15.18 vs. 14.15 tail % DNA, p=0.03). A significantly higher DNA TM was also observed in workers with homozygous Ile-Ile GSTP1 genotype than heterozygous (Ile-Val) and mutant (Val-Val) GSTP1 genotype (p=0.02). In conclusion, the results show that null deletion of GSTM1 and homozygote wild GSTP1 genotype could be related to inter-individual differences in DNA damage arises from the gene-environment interactions in workers occupationally exposed to OPs. 相似文献
7.
Anjali V. Sahasrabudhe Suresh M. Solapure Rajeev Khurana Vepa Suryanarayan Sudha Ravishankar Sunita M. deSousa Goutam Das 《Protein expression and purification》1998,14(3):425-433
hBSSL and its truncated variant hBSSL-C cDNA clones were expressed inPichia pastorisusing two different signal peptides, native signal peptide and invertase signal peptide, respectively, to facilitate secretion of the recombinant proteins into the culture medium. Both recombinant proteins were secreted into the culture medium to a level of 45–50 mg/liter in shake flask cultures. Native signal peptide of hBSSL was recognized inP. pastorisand was cleaved at the same site as in humans. The level of expression of the hBSSL gene was found to be dependent on the number of its copies integrated into the host chromosome. The multicopy transformant clone was found to be very stable. When grown and induced in a fermentor, the level of accumulation of the recombinant hBSSL in the culture medium improved from 50 mg/liter in shake flask cultures to 300 mg/liter. The recombinant hBSSL purified from the culture supernatant was found to be similar to the native hBSSL in its biochemical properties except for the lectin-binding profile. 相似文献
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Bhatnagar Akanksha Singh Shipra Khurana Jitendra P. Burman Naini 《Journal of plant biochemistry and biotechnology.》2020,29(4):590-610
Journal of Plant Biochemistry and Biotechnology - Light acts catalytically to initiate a cascade of events to eventually regulate different aspects of plant development. The cascade of light signal... 相似文献
10.
Blanchoin L Boujemaa-Paterski R Henty JL Khurana P Staiger CJ 《Current opinion in plant biology》2010,13(6):714-723
Gazing at a giant redwood tree in the Pacific Northwest, that has grown to enormous heights over centuries, does little to convince one that plants are built for speed and versatility. Even at the cellular level, a system of polymers-the cell skeleton or cytoskeleton-integrates signals and generates subcellular structures spanning scales of a few nanometers to hundreds of micrometers that coordinate cell growth. The term cytoskeleton itself connotes a stable structure. Clearly, this is not the case. Recent studies using advanced imaging modalities reveal the plant actin cytoskeleton to be a highly dynamic, ever changing assemblage of polymers. These insights along with growing evidence about the biochemical/biophysical properties of plant cytoskeletal polymers, especially those obtained by single filament imaging and reconstituted systems of purified proteins analyzed by total internal reflection fluorescence microscopy, allow the generation of a unique model for the dynamic turnover of actin filaments, termed stochastic dynamics. Here, we review several significant advances and highlight opportunities that will position plants at the vanguard of research on actin organization and turnover. A challenge for the future will be to apply the power of reverse-genetics in several model organisms to test the molecular details of this new model. 相似文献