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排序方式: 共有243条查询结果,搜索用时 15 毫秒
1.
Nabiel A.M. Saleh Zeinab A.R. El-karemy Ragaa M.A. Mansour Abdel-Aziz A. Fayed 《Phytochemistry》1983,22(11):2501-2505
The flavonoids of five Geranium, fourteen Erodium and four Monsonia species were studied. Quercetin was the most common aglycone with lesse 相似文献
2.
Kindlin Is Mechanosensitive: Force-Induced Conformational Switch Mediates Cross-Talk among Integrins
Zeinab Jahed Zainab Haydari Akshay Rathish Mohammad R.K. Mofrad 《Biophysical journal》2019,116(6):1011-1024
Mechanical stresses directly regulate the function of several proteins of the integrin-mediated focal adhesion complex as they experience intra- and extracellular forces. Kindlin is a largely overlooked member of the focal adhesion complex whose roles in cellular mechanotransduction are only recently being identified. Recent crystallographic experiments have revealed that kindlins can form dimers that bind simultaneously to two integrins, providing a mechanistic explanation of how kindlins may promote integrin activation and clustering. In this study, using the newly identified molecular structure, we modeled the response of the kindlin2 dimer in complex with integrin β1 to mechanical cytoskeletal forces on integrins. Using molecular dynamics simulations, we show that forces on integrins are directly transmitted to the kindlin2 dimerization site, resulting in a shift in an R577-S550/E553 interaction network at this site. Under force, R577 on one protomer switches from interacting with S550 to forming new hydrogen bonds with E553 on the neighboring protomer, resulting in the strengthening of the kindlin2 dimer in complex with integrin β1. This force-induced strengthening is similar to the catch-bond mechanisms that have previously been observed in other adhesion molecules. Based on our results, we propose that the kindlin2 dimer is mechanosensitive and can strengthen integrin-mediated focal adhesions under force by shifting the interactions at its dimerization sites. 相似文献
3.
Abdullah Z Geiger S Nino-Castro A Böttcher JP Muraliv E Gaidt M Schildberg FA Riethausen K Flossdorf J Krebs W Chakraborty T Kurts C Schultze JL Knolle PA Klotz L 《PloS one》2012,7(5):e37349
The peroxisomal proliferator-activated receptor γ (PPARγ) is a nuclear receptor that controls inflammation and immunity. Innate immune defense against bacterial infection appears to be compromised by PPARγ. The relevance of PPARγ in myeloid cells, that organize anti-bacterial immunity, for the outcome of immune responses against intracellular bacteria such as Listeria monocytogenes in vivo is unknown. We found that Listeria monocytogenes infection of macrophages rapidly led to increased expression of PPARγ. This prompted us to investigate whether PPARγ in myeloid cells influences innate immunity against Listeria monocytogenes infection by using transgenic mice with myeloid-cell specific ablation of PPARγ (LysMCre×PPARγ(flox/flox)). Loss of PPARγ in myeloid cells results in enhanced innate immune defense against Listeria monocytogenes infection both, in vitro and in vivo. This increased resistance against infection was characterized by augmented levels of bactericidal factors and inflammatory cytokines: ROS, NO, IFNγ TNF IL-6 and IL-12. Moreover, myeloid cell-specific loss of PPARγ enhanced chemokine and adhesion molecule expression leading to improved recruitment of inflammatory Ly6C(hi) monocytes to sites of infection. Importantly, increased resistance against Listeria infection in the absence of PPARγ was not accompanied by enhanced immunopathology. Our results elucidate a yet unknown regulatory network in myeloid cells that is governed by PPARγ and restrains both listeriocidal activity and recruitment of inflammatory monocytes during Listeria infection, which may contribute to bacterial immune escape. Pharmacological interference with PPARγ activity in myeloid cells might represent a novel strategy to overcome intracellular bacterial infection. 相似文献
4.
Zeinab Hamid Andrew Wadsworth Elham Rezasoltani Sarah Holliday Mohammed Azzouzi Marios Neophytou Anne A. Y. Guilbert Yifan Dong Mark S. Little Subhrangsu Mukherjee Andrew A. Herzing Helen Bristow R. Joseph Kline Dean M. DeLongchamp Artem A. Bakulin James R. Durrant Jenny Nelson Iain McCulloch 《Liver Transplantation》2020,10(8)
The temperature‐dependent aggregation behavior of PffBT4T polymers used in organic solar cells plays a critical role in the formation of a favorable morphology in fullerene‐based devices. However, there is little investigation into the impact of donor/acceptor ratio on morphology tuning, especially for nonfullerene acceptors (NFAs). Herein, the influence of composition on morphology is reported for blends of PffBT4T‐2DT with two NFAs, O‐IDTBR and O‐IDFBR. The monotectic phase behavior inferred from differential scanning calorimetry provides qualitative insight into the interplay between solid–liquid and liquid–liquid demixing. Transient absorption spectroscopy suggests that geminate recombination dominates charge decay and that the decay rate is insensitive to composition, corroborated by negligible changes in open‐circuit voltage. Exciton lifetimes are also insensitive to composition, which is attributed to the signal being dominated by acceptor excitons which are formed and decay in domains of similar size and purity irrespective of composition. A hierarchical morphology is observed, where the composition dependence of size scales and scattering intensity from resonant soft X‐ray scattering (R‐SoXS) is dominated by variations in volume fractions of polymer/polymer‐rich domains. Results suggest an optimal morphology where polymer crystallite size and connectivity are balanced, ensuring a high probability of hole extraction via such domains. 相似文献
5.
Masoumi Zeinab Haghighi Maryam Jalali Seyed Amir Hossein 《Molecular biology reports》2021,48(5):4233-4245
Molecular Biology Reports - Both extreme usage of water in agriculture i.e., drought and flooding affect physiological and growth aspects of the plant as well as gene expression undertaken in water... 相似文献
6.
M. Mabrouk Atalla H. Kheiralla Zeinab R. Hamed Eman A. Youssry Amani A. Abd El Aty Abeer 《Saudi Journal of Biological Sciences》2013,20(4):373-381
The properties of Trematosphaeria mangrovei laccase enzyme purified on Sephadex G-100 column were investigated. SDS–PAGE of the purified laccase enzyme showed a single band at 48 kDa. The pure laccase reached its maximal activity at temperature 65 °C, pH 4.0 with Km equal 1.4 mM and Vmax equal 184.84 U/mg protein. The substrate specificity of the purified laccase was greatly influenced by the nature and position of the substituted groups in the phenolic ring. The pure laccase was tested with some metal ions and inhibitors, FeSO4 completely inhibited laccase enzyme and also highly affected by (NaN3) at a concentration of 1 mM. Amino acid composition of the pure enzyme was also determined. Carbohydrate content of purified laccase enzyme was 23% of the enzyme sample. The UV absorption spectra of the purified laccase enzyme showed a single peak at 260–280 nm. 相似文献
7.
Pirh2 is a p53 inducible gene that encodes a RING-H2 domain and is proposed to be a main regulator of p53 protein, thus fine tuning the DNA damage response. Pirh2 interacts physically with p53 and promotes its MDM2-independent ubiquitination and subsequent degradation as well as participates in an auto-regulatory feedback loop that controls p53 function. Pirh2 also self-ubiquitinates. Interestingly, Pirh2 is overexpressed in a wide range of human tumors. In this study, we investigated the domains and residues essential for Pirh2 self-ubiquitination. Deletions were made in each of the three major domains of Pirh2: the N-terminal domain (NTD), Ring domain (RING), and C-terminal domain (CTD). The effects of these deletions on Pirh2 self-ubiquitination were then assessed using in vitro ubiquitination assays. Our results demonstrate that the RING domain is essential, but not sufficient, for Pirh2 self-ubiquitination and that residues 240–250 of the C-terminal domain are also essential. Our results demonstrate that Pirh2 mediated p53 polyubiquitination occurs mainly through the K48 residue of ubiquitin in vitro. Our data further our understanding of the mechanism of Pirh2 self-ubiquitination and may help identify valuable therapeutic targets that play roles in reducing the effects of the overexpression of Pirh2, thus maximizing p53''s response to DNA damage. 相似文献
8.
Habibzadeh Seyyedeh Zahra Salehzadeh Ali Moradi-Shoeili Zeinab Shandiz Seyed Ataollah Sadat 《Molecular biology reports》2020,47(3):1637-1647
Molecular Biology Reports - Gastric cancer is one of the common types of cancer around the world which has few therapeutic options. Nitrogen heterocyclic derivatives such as thiazoles are used as... 相似文献
9.
Shahabzadeh Zeinab Darvishzadeh Reza Mohammadi Reza Jafari Morad 《Plant Molecular Biology Reporter》2020,38(2):175-186
Plant Molecular Biology Reporter - Fifty tall fescue (Festuca arundinacea Schreb.) half-sib families were screened under salinity stress during germination stage, and five tolerant and five... 相似文献
10.
Shahabzadeh Zeinab Darvishzadeh Reza Mohammadi Reza Jafari Morad 《Plant Molecular Biology Reporter》2020,38(2):187-188
Plant Molecular Biology Reporter - The original version of this article unfortunately contained some mistakes in article Title and Table 1. 相似文献