The Coronaviridae family is characterized by a nucleocapsid that is composed of the genome RNA molecule in combination with the nucleoprotein (N protein) within a virion. The most striking physiochemical feature of the N protein of SARS-CoV is that it is a typical basic protein with a high predicted pI and high hydrophilicity, which is consistent with its function of binding to the ribophosphate backbone of the RNA molecule. The predicted high extent of phosphorylation of the N protein on multiple candidate phosphorylation sites demonstrates that it would be related to important functions, such as RNA-binding and localization to the nucleolus of host cells. Subsequent study shows that there is an SR-rich region in the N protein and this region might be involved in the protein-protein interaction. The abundant antigenic sites predicted in the N protein, as well as experimental evidence with synthesized polypeptides, indicate that the N protein is one of the major antigens of the SARS-CoV. Compared with o 相似文献
Human serum albumin (HSA) and human parathyroid hormone (1-34) [PTH (1-34)] fusion protein [HSA/PTH (1-34)] is a promising long-acting form of PTH (1-34) for osteoporosis treatment. Secretory expression of intact HSA/PTH (1-34) in Pichia pastoris GS115 was accompanied by two degradation fragments, with molecular weights around 66 kDa, in addition to the well-known ~45 kDa HSA-truncated fragment, resulting in a low yield of intact protein. In this study, two internal cleavage sites were identified in the PTH (1-34) portion of the fusion protein by Western Blot analysis. To minimize proteolytic cleavages, several protease genes including PEP4 (encoding proteinase A), PRB1 (proteinase B) and seven YPSs genes (yapsin family members) were knocked out respectively by disruption of the individual genes and the selective combinations. Reduced degradation was observed by single disruption of either PEP4 gene or YPS1 gene, and the lowest level of degradation was observed in a pep4△yps1△ double disruptant. After 72 h of induction, more than 80 % of the HSA/PTH (1-34) secreted by the pep4△yps1△ double disruptant remained intact, in comparison to only 30 % with the wild-type strain. 相似文献
Plant Molecular Biology Reporter - The j allele delays flowering and enhances yield of long juvenile (LJ) soybean under short day (SD) condition. However, the underlying mechanism of j in flowering... 相似文献
Ultrasound is widely used in biomedical engineering and has applications in conventional diagnosis and drug delivery. Recent advances in ultrasound-induced drug delivery have been summarized previously in several reviews that have primarily focused on the fabrication of drug delivery carriers. This review discusses the mechanisms underlying ultrasound-induced drug delivery and factors affecting delivery efficiency, including the characteristics of drug delivery carriers and ultrasound parameters. Firstly, biophysical effects induced by ultrasound, namely thermal effects, cavitation effects, and acoustic radiation forces, are illustrated. Secondly, the use of these biophysical effects to enhance drug delivery by affecting drug carriers and corresponding tissues is clarified in detail. Thirdly, recent advances in ultrasound-triggered drug delivery are detailed. Safety issues and optimization strategies to improve therapeutic outcomes and reduce side effects are summarized. Finally, current progress and future directions are discussed.
Recently, the application of electron backscatter diffraction (EBSD) in halide perovskites has enabled the correlation of the micro‐structural arrangement of polycrystalline grains with other properties (optical, electrical, mechanical, and chemical) in a “pixel‐by‐pixel” approach. Most studies so far have used an ultra‐sensitive electron beam detector that has sensitivity thousands of times higher than a traditional scintillator screen and charge coupled device camera, enabling much lower beam currents. An alternative approach has been the use of low vacuum measurement conditions to avoid charge buildup that leads to damage. This review focuses on introducing the classical EBSD technique to the halide perovskite community, where it has been highly underutilized due to beaminduced damage in these relatively unstable materials. Recent research is used to dispel some common misconceptions about grain boundaries in halide perovskites and highlight what has been learned by comparing and correlating EBSD with other techniques. Additionally, the remaining limitations, development challenges, and future of the EBSD technique for halide perovskites are discussed. Successful utilization of the EBSD technique as a common characterization tool in the halide perovskite community will enable scientists and engineers to develop maps of cross correlated properties, helping to unlock the full potential of this complex material system. 相似文献
It is well documented that liver is the primary target organ of aflatoxin B1 (AFB1) and curcumin proved to be effective against AFB1-induced liver injury. In the present study, we investigated the preventive effects of curcumin against AFB1-induced apoptosis through the molecular regulation of p53, caspase-3, Bax, caspase-9, Bcl-2 and cytochrome-C associated with mitochondrial pathway. Liver antioxidant levels were measured. The hallmarks of apoptosis were analysed by methyl green-pyronin-Y staining, transmission electron microscopy, RT-PCR and western blot. Results revealed that dietary curcumin ameliorated AFB1-induced oxidative stress in a dose-dependent manner. Methyl green-pyronin-Y staining and transmission electron microscopy showed that AFB1 induced apoptosis and caused abnormal changes in liver cells morphology such as condensation of chromatin material, reduces cell volume and damaged mitochondria. Moreover, mRNA and protein expression results manifested that apoptosis associated genes showed up-regulation in AFB1 fed group. However, the supplementation of dietary curcumin (dose-dependently) alleviated the increased expression of the apoptosis associated genes at mRNA and protein level, and restored the hepatocytes normal morphology. The study provides an insight and a better understanding of the preventive mechanism of curcumin against AFB1-induced apoptosis in hepatocytes and provide scientific basis for the therapeutic uses of curcumin.
A series of purine derivatives with nitramine groups are calculated by using density functional theory (DFT). The molecular theory density, heats of formation, bond dissociation energies and detonation performance are investigated at DFT-B3LYP/6-311G** level. The isodesmic reaction method is employed to calculate the HOFs of the energies obtained from electronic structure calculations. Results show that the position of nitramine groups can influence the values of HOFs. The bond dissociation energies and the impact sensitivity are analyzed to investigate the thermal stability of the purine derivatives. The calculated bond dissociation energies of ring-NHNO2 and NH-NO2 bond show that the NH-NO2 bond should be the trigger bond in pyrolysis processes. The H50 of most compounds are larger than that of CL-20 and RDX. 相似文献