排序方式: 共有9条查询结果,搜索用时 15 毫秒
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Loai M. Saadah Ghinaa I. Abu Deiab Qosay Al-Balas Iman A. Basheti 《Molecules (Basel, Switzerland)》2020,25(23)
Aims: Angiotensin-converting enzyme 2 (ACE2) plays an important role in the entry of coronaviruses into host cells. The current paper described how carnosine, a naturally occurring supplement, can be an effective drug candidate for coronavirus disease (COVID-19) on the basis of molecular docking and modeling to host ACE2 cocrystallized with nCoV spike protein. Methods: First, the starting point was ACE2 inhibitors and their structure–activity relationship (SAR). Next, chemical similarity (or diversity) and PubMed searches made it possible to repurpose and assess approved or experimental drugs for COVID-19. Parallel, at all stages, the authors performed bioactivity scoring to assess potential repurposed inhibitors at ACE2. Finally, investigators performed molecular docking and modeling of the identified drug candidate to host ACE2 with nCoV spike protein. Results: Carnosine emerged as the best-known drug candidate to match ACE2 inhibitor structure. Preliminary docking was more optimal to ACE2 than the known typical angiotensin-converting enzyme 1 (ACE1) inhibitor (enalapril) and quite comparable to known or presumed ACE2 inhibitors. Viral spike protein elements binding to ACE2 were retained in the best carnosine pose in SwissDock at 1.75 Angstroms. Out of the three main areas of attachment expected to the protein–protein structure, carnosine bound with higher affinity to two compared to the known ACE2 active site. LibDock score was 92.40 for site 3, 90.88 for site 1, and inside the active site 85.49. Conclusion: Carnosine has promising inhibitory interactions with host ACE2 and nCoV spike protein and hence could offer a potential mitigating effect against the current COVID-19 pandemic. 相似文献
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Suliman Al-Homidan Nicolas Hadjisavvas Loai Shaalan 《Journal of Optimization Theory and Applications》2018,177(1):93-105
Quasiconvex functions present some difficulties in global optimization, because their graph contains “flat parts”; thus, a local minimum is not necessarily the global minimum. In this paper, we show that any lower semicontinuous quasiconvex function may be written as a composition of two functions, one of which is nondecreasing, and the other is quasiconvex with the property that every local minimum is global minimum. Thus, finding the global minimum of any lower semicontinuous quasiconvex function is equivalent to finding the minimum of a quasiconvex function, which has no local minima other than its global minimum. The construction of the decomposition is based on the notion of “adjusted sublevel set.” In particular, we study the structure of the class of sublevel sets, and the continuity properties of the sublevel set operator and its corresponding normal operator. 相似文献
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Alexander D. Fusi Yudong Li Dr. A. Llopis-Lorente Dr. Tania Patiño Prof. Dr. Jan C. M. van Hest Dr. Loai K. E. A. Abdelmohsen 《Angewandte Chemie (International ed. in English)》2023,62(5):e202214754
Unprecedented opportunities exist for the generation of advanced nanotechnologies based on synthetic micro/nanomotors (MNMs), such as active transport of medical agents or the removal of pollutants. In this regard, great efforts have been dedicated toward controlling MNM motion (e.g., speed, directionality). This was generally performed by precise engineering and optimizing of the motors′ chassis, engine, powering mode (i.e., chemical or physical), and mechanism of motion. Recently, new insights have emerged to control motors mobility, mainly by the inclusion of different modes that drive propulsion. With high degree of synchronization, these modes work providing the required level of control. In this Minireview, we discuss the diverse factors that impact motion; these include MNM morphology, modes of mobility, and how control over motion was achieved. Moreover, we highlight the main limitations that need to be overcome so that such motion control can be translated into real applications. 相似文献
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Lasse Hunger Loai Al-Sheakh Dr. Dzmitry H. Zaitsau Prof. Dr. Sergey P. Verevkin Andreas Appelhagen Dr. Alexander Villinger Prof. Dr. Ralf Ludwig 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(46):e202200949
We show that the carboxyl-functionalized ionic liquid 1-(carboxymethyl)pyridinium bis(trifluoromethylsulfonyl)imide [HOOC-CH2-py][NTf2] exhibits three types of hydrogen bonding: the expected single hydrogen bonds between cation and anion, and, surprisingly, single and double hydrogen bonds between the cations, despite the repulsive Coulomb forces between the ions of like charge. Combining X-ray crystallography, differential scanning calorimetry, IR spectroscopy, thermodynamic methods and DFT calculations allows the analysis and characterization of all types of hydrogen bonding present in the solid, liquid and gaseous states of the ionic liquid (IL). We find doubly hydrogen bonded cationic dimers (c+=c+) in the crystalline phase. With increasing temperature, this binding motif opens in the liquid and is replaced by (c+−c+−a− species, with a remaining single cationic hydrogen bond and an additional hydrogen bond between cation and anion. We provide clear evidence that the IL evaporates as hydrogen-bonded ion pairs (c+−a−) into the gas phase. The measured transition enthalpies allow the noncovalent interactions to be dissected and the hydrogen bond strength between ions of like charge to be determined. 相似文献
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Jingxin Shao Shoupeng Cao David S. Williams Loai K. E. A. Abdelmohsen Jan C. M. van Hest 《Angewandte Chemie (International ed. in English)》2020,59(39):16918-16925
Synthetic nanomotors are appealing delivery vehicles for the dynamic transport of functional cargo. Their translation toward biological applications is limited owing to the use of non‐degradable components. Furthermore, size has been an impediment owing to the importance of achieving nanoscale (ca. 100 nm) dimensions, as opposed to microscale examples that are prevalent. Herein, we present a hybrid nanomotor that can be activated by near‐infrared (NIR)‐irradiation for the triggered delivery of internal cargo and facilitated transport of external agents to the cell. Utilizing biodegradable poly(ethylene glycol)‐b‐poly(d,l ‐lactide) (PEG‐PDLLA) block copolymers, with the two blocks connected via a pH sensitive imine bond, we generate nanoscopic polymersomes that are then modified with a hemispherical gold nanocoat. This Janus morphology allows such hybrid polymersomes to undergoing photothermal motility in response to thermal gradients generated by plasmonic absorbance of NIR irradiation, with velocities ranging up to 6.2±1.10 μm s?1. These polymersome nanomotors (PNMs) are capable of traversing cellular membranes allowing intracellular delivery of molecular and macromolecular cargo. 相似文献
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Hailong Che Jianzhi Zhu Shidong Song Alexander F. Mason Shoupeng Cao Imke A. B. Pijpers Loai K. E. A. Abdelmohsen Jan C. M. van Hest 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(37):13247-13252
In nature, dynamic processes are ubiquitous and often characterized by adaptive, transient behavior. Herein, we present the development of a transient bowl‐shaped nanoreactor system, or stomatocyte, the properties of which are mediated by molecular interactions. In a stepwise fashion, we couple motility to a dynamic process, which is maintained by transient events; namely, binding and unbinding of adenosine triphosphate (ATP). The surface of the nanosystem is decorated with polylysine (PLL), and regulation is achieved by addition of ATP. The dynamic interaction between PLL and ATP leads to an increase in the hydrophobicity of the PLL–ATP complex and subsequently to a collapse of the polymer; this causes a narrowing of the opening of the stomatocytes. The presence of the apyrase, which hydrolyzes ATP, leads to a decrease of the ATP concentration, decomplexation of PLL, and reopening of the stomatocyte. The competition between ATP input and consumption gives rise to a transient state that is controlled by the out‐of‐equilibrium process. 相似文献
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Bastiaan C. Buddingh' Antoni Llopis-Lorente Loai K. E. A. Abdelmohsen Jan C. M. van Hest 《Chemical science》2020,11(47):12829
Structural and spatial organization are fundamental properties of biological systems that allow cells to regulate a wide range of biochemical processes. This organization is often transient and governed by external cues that initiate dynamic self-assembly processes. The construction of synthetic cell-like materials with similar properties requires the hierarchical and reversible organization of selected functional components on molecular scaffolds to dynamically regulate signaling pathways. The realization of such transient molecular programs in synthetic cells, however, remains underexplored due to the associated complexity of such hierarchical platforms. In this contribution, we effectuate dynamic spatial organization of effector protein subunits in a synthetic biomimetic compartment, a giant unilamellar vesicle (GUV), by associating in a reversible manner two fragments of a split luciferase to the membrane. This induces their structural dimerization, which consequently leads to the activation of enzymatic signaling. Importantly, such organization and activation are dynamic processes, and can be autonomously regulated – thus opening up avenues toward continuous spatiotemporal control over supramolecular organization and signaling in an artificial cell.Engineered artificial cells respond to environmental cues through a pre-programmed enzymatic machinery that induces spatio-structural organization and activation of effector proteins at the lipid membrane. 相似文献
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Loai Al Sheakh Dr. Thomas Niemann Dr. Alexander Villinger Peter Stange Dr. Dzmitry H. Zaitsau Dr. Anne Strate Prof. Dr. Ralf Ludwig 《Chemphyschem》2021,22(18):1850-1856
The paradigm of supramolecular chemistry relies on the delicate balance of noncovalent forces. Here we present a systematic approach for controlling the structural versatility of halide salts by the nature of hydrogen bonding interactions. We synthesized halide salts with hydroxy-functionalized pyridinium cations [HOCnPy]+ (n=2, 3, 4) and chloride, bromide and iodide anions, which are typically used as precursor material for synthesizing ionic liquids by anion metathesis reaction. The X-ray structures of these omnium halides show two types of hydrogen bonding: ‘intra-ionic’ H-bonds, wherein the anion interacts with the hydroxy group and the positively charged ring at the same cation, and ‘inter-ionic’ H-bonds, wherein the anion also interacts with the hydroxy group and the ring system but of different cations. We show that hydrogen bonding is controllable by the length of the hydroxyalkyl chain and the interaction strength of the anion. Some molten halide salts exhibit a third type of hydrogen bonding. IR spectra reveal elusive H-bonds between the OH groups of cations, showing interaction between ions of like charge. They are formed despite the repulsive interaction between the like-charged ions and compete with the favored cation-anion H-bonds. All types of H-bonding are analyzed by quantum chemical methods and the natural bond orbital approach, emphasizing the importance of charge transfer in these interactions. For simple omnium salts, we evidenced three distinct types of hydrogen bonds: Three in one! 相似文献
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