排序方式: 共有35条查询结果,搜索用时 15 毫秒
21.
Mark T McAuley Rose Anne Kenny Thomas BL Kirkwood Darren J Wilkinson Janette JL Jones Veronica M Miller 《BMC neuroscience》2009,10(1):26
Background
The hippocampus is essential for declarative memory synthesis and is a core pathological substrate for Alzheimer's disease (AD), the most common aging-related dementing disease. Acute increases in plasma cortisol are associated with transient hippocampal inhibition and retrograde amnesia, while chronic cortisol elevation is associated with hippocampal atrophy. Thus, cortisol levels could be monitored and managed in older people, to decrease their risk of AD type hippocampal dysfunction. We generated an in silicomodel of the chronic effects of elevated plasma cortisol on hippocampal activity and atrophy, using the systems biology mark-up language (SBML). We further challenged the model with biologically based interventions to ascertain if cortisol associated hippocampal dysfunction could be abrogated. 相似文献22.
B. P. Nicolsky V. I. Paramonova A. Stock H. Th. St. Britton C. Naegeli A. Tyabji Soerensen Walbum Ringer J. M. Kolthoff L. V. Wilcox B. Cavanagh B. Diethelm F. Foerster T. Callan J. A. Russell Henderson C. Robinson O. L. Evenson R. H. Nagel D. T. Mc Cutchen J. A. Atanasiu A. I. Verculescu R. R. Ralston C. H. Fellows K. S. Wyatt H. Seltz D. S. Mc Kinney K. Masaki C. del Fresno E. Mairlot E. Jimeno und J. Ibarz 《Fresenius' Journal of Analytical Chemistry》1932,90(7-8):281-287
Ohne Zusammenfassung 相似文献
23.
Teng‐Teng Chen Ling Fung Cheung Wei‐Jia Chen Joseph Cavanagh Lai‐Sheng Wang 《Angewandte Chemie (International ed. in English)》2020,59(35):15260-15265
Multiple bonds between boron and transition metals are known in many borylene (:BR) complexes via metal dπ→BR back‐donation, despite the electron deficiency of boron. An electron‐precise metal–boron triple bond was first observed in BiB2O? [Bi≡B?B≡O]? in which both boron atoms can be viewed as sp‐hybridized and the [B?BO]? fragment is isoelectronic to a carbyne (CR). To search for the first electron‐precise transition‐metal‐boron triple‐bond species, we have produced IrB2O? and ReB2O? and investigated them by photoelectron spectroscopy and quantum‐chemical calculations. The results allow to elucidate the structures and bonding in the two clusters. We find IrB2O? has a closed‐shell bent structure (Cs, 1A′) with BO? coordinated to an Ir≡B unit, (?OB)Ir≡B, whereas ReB2O? is linear (C∞v, 3Σ?) with an electron‐precise Re≡B triple bond, [Re≡B?B≡O]?. The results suggest the intriguing possibility of synthesizing compounds with electron‐precise M≡B triple bonds analogous to classical carbyne systems. 相似文献
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Teng-Teng Chen Ling Fung Cheung Wei-Jia Chen Joseph Cavanagh Prof. Dr. Lai-Sheng Wang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(35):15372-15377
Multiple bonds between boron and transition metals are known in many borylene (:BR) complexes via metal dπ→BR back-donation, despite the electron deficiency of boron. An electron-precise metal–boron triple bond was first observed in BiB2O− [Bi≡B−B≡O]− in which both boron atoms can be viewed as sp-hybridized and the [B−BO]− fragment is isoelectronic to a carbyne (CR). To search for the first electron-precise transition-metal-boron triple-bond species, we have produced IrB2O− and ReB2O− and investigated them by photoelectron spectroscopy and quantum-chemical calculations. The results allow to elucidate the structures and bonding in the two clusters. We find IrB2O− has a closed-shell bent structure (Cs, 1A′) with BO− coordinated to an Ir≡B unit, (−OB)Ir≡B, whereas ReB2O− is linear (C∞v, 3Σ−) with an electron-precise Re≡B triple bond, [Re≡B−B≡O]−. The results suggest the intriguing possibility of synthesizing compounds with electron-precise M≡B triple bonds analogous to classical carbyne systems. 相似文献
25.
Soderblom EJ Bobay BG Cavanagh J Goshe MB 《Rapid communications in mass spectrometry : RCM》2007,21(21):3395-3408
Chemical crosslinking combined with mass spectrometry is a useful tool for studying the topological organization of multiprotein interactions, but it is technically challenging to identify peptides involved in a crosslink using tandem mass spectrometry (MS/MS) due to the presence of product ions originating from both peptides within the same crosslink. We have previously developed a novel set of collision-induced dissociative chemical crosslinking reagents (CID-CXL reagents) that incorporate a labile bond within the linker which readily dissociates at a single site under low-energy collision-induced dissociation (CID) to enable independent isolation and sequencing of the crosslinked peptides by traditional MS/MS and database searching. Alternative low-energy CID events were developed within the in-source region by increasing the multipole DC offset voltage (ISCID) or within the ion trap by increasing the collisional excitation (ITCID). Both dissociation events, each having their unique advantages, occur without significant backbone fragmentation to the peptides, thus permitting subsequent CID to be applied to these distinct peptide ions for generation of suitable product ion spectra for database searching. Each approach was developed and applied to a chemical crosslinking study involving the N-terminal DNA-binding domain of AbrB (AbrBN), a transition-state regulator in Bacillus subtilis. A total of thirteen unique crosslinks were identified using the ITCID approach which represented a significant improvement over the eight unique crosslinks identified using the ISCID approach. The ability to segregate intrapeptide and interpeptide crosslinks using ITCID represents the first step towards high-throughput analysis of protein-protein crosslinks using our CID-CXL reagents. 相似文献
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Benson LM Kumar R Cavanagh J Naylor S 《Rapid communications in mass spectrometry : RCM》2003,17(4):267-271
The modulation of metal ions on protein function is well recognized and of paramount importance in protein biochemistry. To date, very few methods allow direct determination of protein-metal ion interactions, as well as exact stoichiometric binding ratios. In this work we demonstrate the usefulness of two on-line size exclusion gel filtration mass spectrometry approaches to directly detect protein-metal ion adducts, as well as determine exact protein-metal ion stoichiometries. We show that on-line size exclusion column chromatography (SEC) and rapid in-line desalting (RILED) coupled to microelectrospray mass spectrometry (microESI-MS) can be used for such analyses. The SEC approach can be effectively used to both separate proteins in a complex mixture and exchange buffers prior to the electrospray process. While RILED does not allow for protein separation, it provides a much faster high-throughput desalting procedure than the conventional SEC technique. Specifically, we show that SEC/microESI-MS and RILED/MS can be used to determine calcium ion binding stoichiometries to a high-affinity, metal ion binding protein, calbindin D(28K). Furthermore, the same approaches can also be used to determine metal ion binding stoichiometries of low-affinity metal-binding proteins such as Spo0F. 相似文献
29.
Venters RA Coggins BE Kojetin D Cavanagh J Zhou P 《Journal of the American Chemical Society》2005,127(24):8785-8795
Projection-reconstruction NMR experiments have been shown to significantly reduce the acquisition time required to obtain protein backbone assignment data. To date, this concept has only been applied to smaller (15)N/(13)C-labeled proteins. Here, we show that projection-reconstruction NMR techniques can be extended to larger protonated and perdeuterated proteins. We present a suite of (4,2)D triple-resonance experiments for protein backbone assignment and a Hybrid Backprojection/Lower-Value algorithm for reconstructing data with relatively weak signal-to-noise ratios. In addition, we propose a sampling theorem and discuss its implication on the choice of projection angles. We demonstrate the efficacy of this approach using the 29 kDa protein, human carbonic anhydrase II and the 30 kDa protein, calbindin D(28K). 相似文献
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