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961.
Wada K Takeuchi A Saiki K Sutomo R Van Rostenberghe H Yusoff NM Laosombat V Sadewa AH Talib NA Yusoff S Lee MJ Ayaki H Nakamura H Matsuo M Nishio H 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2006,838(1):9-14
Mutations in the gene encoding UDP-glucuronosyltransferase 1A1 (UGT1A1) may reduce the glucuronidation of estradiol, bilirubin, etc. In the present study, we used a liquid chromatography-tandem mass spectrometry (LC/MS/MS) method to assay the activities of recombinant mutated UGT1A1 toward 17beta-estradiol (E2), by determining its glucuronide (E2G) content. Direct evidence for glucuronide formation was provided by E2G-specific ion peaks. The UGT1A1 activities of G71R (exon 1), F83L (exon 1), I322V (exon 2) and G493R (exon 5) mutants were 24, 30, 18 and 0.6% of the normal UGT1A1 activity, respectively. In conclusion, our study showed that LC/MS/MS enabled accurate evaluation of the effects of mutations on recombinant UGT1A1 activity towards E2. 相似文献
962.
963.
Joshi MC Sharma A Kant S Birah A Gupta GP Khan SR Bhatnagar R Banerjee N 《The Journal of biological chemistry》2008,283(42):28287-28296
Xenorhabdus nematophila secretes insecticidal proteins to kill its larval prey. We have isolated an approximately 58-kDa GroEL homolog, secreted in the culture medium through outer membrane vesicles. The protein was orally insecticidal to the major crop pest Helicoverpa armigera with an LC50 of approximately 3.6 microg/g diet. For optimal insecticidal activity all three domains of the protein, apical, intermediate, and equatorial, were necessary. The apical domain alone was able to bind to the larval gut membranes and manifest low level insecticidal activity. At equimolar concentrations, the apical domain contained approximately one-third and the apical-intermediate domain approximately one-half bioactivity of that of the full-length protein. Interaction of the protein with the larval gut membrane was specifically inhibited by N-acetylglucosamine and chito-oligosaccharides. Treatment of the larval gut membranes with chitinase abolished protein binding. Based on the three-dimensional structural model, mutational analysis demonstrated that surface-exposed residues Thr-347 and Ser-356 in the apical domain were crucial for both binding to the gut epithelium and insecticidal activity. Double mutant T347A,S356A was 80% less toxic (p < 0.001) than the wild type protein. The GroEL homolog showed alpha-chitin binding activity with Kd approximately 0.64 microm and Bmax approximately 4.68 micromol/g chitin. The variation in chitin binding activity of the mutant proteins was in good agreement with membrane binding characteristics and insecticidal activity. The less toxic double mutant XnGroEL showed an approximately 8-fold increase of Kd in chitin binding assay. Our results demonstrate that X. nematophila secretes an insecticidal GroEL protein with chitin binding activity. 相似文献
964.
Mohd Faizan Siddiqui Mohd Shahnawaz Khan Fohad Mabood Husain 《Journal of biomolecular structure & dynamics》2019,37(9):2230-2241
Carbendazim is a benzimidazole fungicide used to control the fungal invasion. However, its exposure might lead to potential health problems. The present study evaluates the interaction of carbendazim (CAR) with human serum albumin (HSA) which is an important drug carrier protein and plays a very crucial role in the transportation of small molecules. A number of biophysical techniques were employed to investigate the binding of CAR with HSA. The increased UV-absorption of HSA on titrating with CAR suggests the formation of HSA–CAR complex and it could be due to the exposure of aromatic residues. The fluorescence study confirmed that CAR quenches the fluorescence of HSA and showed the static mode of quenching. CAR (50 µM) quenches around 56.14% of the HSA fluorescence. The quenching constant, binding constant, number of binding site and free energy change was calculated by fluorescence quenching experiment. Competitive displacement assay showed Sudlow’s site I as the primary binding site of CAR on HSA. The synchronous fluorescence study revealed the perturbation in the microenvironment around tyrosine and tryptophan residues upon binding of CAR to HSA. The circular dichroism results suggested that the binding of CAR to HSA altered its secondary structure. Molecular docking experiment demonstrated the binding of CAR to Sudlow’s site I of HSA. Docking studies suggested that the hydrogen bonding, van der Waals and pi-alkyl are playing role in the interaction of CAR with HSA. The study confirmed the conformational changes within HSA upon binding of CAR. 相似文献
965.
Khan NA 《Molecular & general genetics : MGG》1975,136(1):55-61
Temperature-sensitive mutants affecting maltose utilization in the yeast Saccharomyces cerevisiae have been isolated. Two such mutants although failing to ferment maltose at the restrictive temperature, have normal induced level of maltase. The third mutant (UNT-37) not only failed to ferment maltose but has 5-6 fold less induced level of maltase at the restrictive temperature than the parental strain. The genetic control mechanisms of maltase induction and maltose utilization have been discussed. 相似文献
966.
Ammar Almaaytah Adan Alnaamneh Ahmad Abualhaijaa Nizar Alshari’ Qosay Al-Balas 《International journal of peptide research and therapeutics》2016,22(4):497-504
The extensive use of antibiotics for the treatment of human infections during the last few decades has led to a dramatic increase in the emergence of multidrug-resistant bacteria (MDRB) among various bacterial strains. Global research is currently focused on finding novel alternative agents with different mechanisms of action rather than the use of conventional antibiotics to counteract the threat of bacterial and biofilm infections. Antimicrobial peptides represent promising alternative agents for conventional antibiotics as these molecules display a broad spectrum of activity against several microorganisms. Recently, we have designed a novel hybrid antimicrobial peptide named MelitAP-27. This peptide has been found to display potent broad spectrum and selective in vitro antimicrobial activities against a wide range of Gram-positive and Gram-negative bacteria. In the present study, the in vitro antimicrobial and antibiofilm activities of the peptide alone and in combination with five different types of antibiotics were assessed against wild-type and resistant Gram-positive and Gram-negative bacterial strains. Our results showed that most of the combination groups displayed a synergistic mode of action against planktonic and biofilm forming bacteria which resulted in decreasing the effective MIC values for MelitAP-27 to the nanomolar concentrations. These effective concentrations were associated with negligible toxicities on mammalian cells. The results of our study indicate that combinations of MelitAP-27 with conventional antibiotics may be pursued as a potential novel treatment strategy against MDRB and biofilm forming bacteria. 相似文献
967.
Jianfan Sun Susan Rutherford Muhammad Saif Ullah Ikram Ullah Qaiser Javed Ghulam Rasool Muhammad Ajmal Ahmad Azeem Muhammad Junaid Nazir Daolin Du 《Journal of Plant Ecology》2022,15(3):610
生物入侵过程中的植物-土壤反馈:一种入侵植物的凋落物分解对其本地近缘植物的影响
植物入侵可通过正或负的植物-土壤反馈效应改变土壤的生物和非生物性质,从而影响入侵栖息地的土壤理化性质。许多入侵物种的凋落物分解可增加土壤养分,降低本地植物多样性,并导致进一步的植物入侵。关于入侵植物凋落物在不同土壤类型及深度分解及反馈效应的研究依然很少。本研究旨在明确入侵植物南美蟛蜞菊(Sphagneticola trilobata)凋落物在不同土壤类型和不同土壤深度条件下的分解情 况及其对本地近缘植物蟛蜞菊(S. calendulacea)生理生长的影响。将装有南美蟛蜞菊凋落物的尼龙袋加入到不同深度(即0、2、4 和6 cm)的砂土、营养土和粘土中,经6个月的分解后,回收凋落物袋并计算分解速率,随后在凋落物分解处理后的土壤中种植本地蟛蜞菊,并在生长期结束时测量其生理生态指标。研究结果表明,所有处理土壤类型中,凋落物在土壤深度为2和4 cm处分解后显著增加了土壤养分,而对本 地蟛蜞菊的叶片叶绿素、叶氮含量等生长指标表现为负效应。因此,入侵植物南美蟛蜞菊凋落物分解对土壤养分表现为正的反馈效应,而对本地植物蟛蜞菊的生长表现为负效应。我们的研究结果还表明,入侵植物的凋落物分解对土壤和本地物种的影响还因凋落物分解所在的土壤深度而显著不同。未来的研究应侧重于入侵栖息地中更多本地和入侵物种的植物-土壤反馈效应,以及更多土壤类型和土壤深度的入侵植物凋落物效应。 相似文献
968.
969.
Tauqeer Ahmad Yasir Sobia Aslam Muhammad Shahid Rizwan Allah Wasaya Muhammad Ateeq Muhammad Naeem Khan Sikander Khan Tanveer Walid Soufan Basharat Ali Allah Ditta Arpna Kumari Ayman EL Sabagh 《Phyton》2022,91(11):2491-2504
In soil biota, higher and enduring concentration of heavy metals like cadmium (Cd) is hazardous and associated
with great loss in growth, yield, and quality parameters of most of the crop plants. Recently, in-situ applications of
eco-friendly stabilizing agents in the form of organic modifications have been utilized to mitigate the adverse
effects of Cd-toxicity. This controlled experiment was laid down to appraise the imprints of various applied
organic amendments namely poultry manure (PM), farmyard manure (FYM), and sugarcane press mud (PS)
to immobilize Cd in polluted soil. Moreover, phytoavailability of Cd in wheat was also accessed under an alkaline
environment. Results revealed that the addition of FYM (5–10 ton ha-1
) in Cd-contaminated soil significantly
increased germination rate, leaf chlorophyll content, plant height, spike length, biological and grain yield amongst
all applied organic amendments. Moreover, the addition of FYM (5–10 ton ha-1
) also reduced the phytoavailability of Cd by 73–85% in the roots, 57–83% in the shoots, and 81–90% in grains of wheat crop. Thus, it is affirmed
that incorporation of FYM (5–10 ton ha-1
) performed better to enhance wheat growth and yield by remediating
Cd. Thus, the application of FYM (5–10 ton ha-1
) reduced the toxicity induced by Cd to plants by declining its
uptake and translocation as compared to all other applied organic amendments to immobilize Cd under sandy
alkaline polluted soil. 相似文献
970.
Setayesh-Mehr Zahra Asoodeh Ahmad 《International journal of peptide research and therapeutics》2019,25(4):1333-1341
International Journal of Peptide Research and Therapeutics - In this study, the effect of peptides HL-7 and HL-10 was examined on human breast cancer cells (MCF-7 cell line) in the presence and... 相似文献