Biocatalytic Cross-Coupling of Aryl Halides with a Genetically Engineered Photosensitizer Artificial Dehalogenase.
Fu Yu,Huang Jian,Wu Yuzhou,Liu Xiaohong,Zhong Fangrui,Wang Jiangyun
Journal of the American Chemical Society
Devising artificial photoenzymes for abiological bond-forming reactions is of high synthetic value but also a tremendous challenge. Disclosed herein is the first photobiocatalytic cross-coupling of aryl halides enabled by a designer artificial dehalogenase, which features a genetically encoded benzophenone chromophore and site-specifically modified synthetic Ni(bpy) cofactor with tunable proximity to streamline the dual catalysis. Transient absorption studies suggest the likelihood of energy transfer activation in the elementary organometallic event. This design strategy is viable to significantly expand the catalytic repertoire of artificial photoenzymes for useful organic transformations.
10.1021/jacs.0c10882
Visualizing in situ translational activity for identifying and sorting slow-growing archaeal-bacterial consortia.
Hatzenpichler Roland,Connon Stephanie A,Goudeau Danielle,Malmstrom Rex R,Woyke Tanja,Orphan Victoria J
Proceedings of the National Academy of Sciences of the United States of America
To understand the biogeochemical roles of microorganisms in the environment, it is important to determine when and under which conditions they are metabolically active. Bioorthogonal noncanonical amino acid tagging (BONCAT) can reveal active cells by tracking the incorporation of synthetic amino acids into newly synthesized proteins. The phylogenetic identity of translationally active cells can be determined by combining BONCAT with rRNA-targeted fluorescence in situ hybridization (BONCAT-FISH). In theory, BONCAT-labeled cells could be isolated with fluorescence-activated cell sorting (BONCAT-FACS) for subsequent genetic analyses. Here, in the first application, to our knowledge, of BONCAT-FISH and BONCAT-FACS within an environmental context, we probe the translational activity of microbial consortia catalyzing the anaerobic oxidation of methane (AOM), a dominant sink of methane in the ocean. These consortia, which typically are composed of anaerobic methane-oxidizing archaea (ANME) and sulfate-reducing bacteria, have been difficult to study due to their slow in situ growth rates, and fundamental questions remain about their ecology and diversity of interactions occurring between ANME and associated partners. Our activity-correlated analyses of >16,400 microbial aggregates provide the first evidence, to our knowledge, that AOM consortia affiliated with all five major ANME clades are concurrently active under controlled conditions. Surprisingly, sorting of individual BONCAT-labeled consortia followed by whole-genome amplification and 16S rRNA gene sequencing revealed previously unrecognized interactions of ANME with members of the poorly understood phylum Verrucomicrobia This finding, together with our observation that ANME-associated Verrucomicrobia are found in a variety of geographically distinct methane seep environments, suggests a broader range of symbiotic relationships within AOM consortia than previously thought.
10.1073/pnas.1603757113
Detection and Quantification of Antimicrobial-Resistant Cells in Aquatic Environments by Bioorthogonal Noncanonical Amino Acid Tagging.
Environmental science & technology
Aquatic environments are important reservoirs of antibiotic wastes, antibiotic resistance genes, and bacteria, enabling the persistence and proliferation of antibiotic resistance in different bacterial populations. To prevent the spread of antibiotic resistance, effective approaches to detect antimicrobial susceptibility in aquatic environments are highly desired. In this work, we adopt a metabolism-based bioorthogonal noncanonical amino acid tagging (BONCAT) method to detect, visualize, and quantify active antimicrobial-resistant bacteria in water samples by exploiting the differences in bacterial metabolic responses to antibiotics. The BONCAT approach can be applied to rapidly detect bacterial resistance to multiple antibiotics within 20 min of incubation, regardless of whether they act on proteins or DNA. In addition, the combination of BONCAT with the microscope enables the intuitive characterization of antibiotic-resistant bacteria in mixed systems at single-cell resolution. Furthermore, BONCAT coupled with flow cytometry exhibits good performance in determining bacterial resistance ratios to chloramphenicol and population heterogeneity in hospital wastewater samples. In addition, this approach is also effective in detecting antibiotic-resistant bacteria in natural water samples. Therefore, such a simple, fast, and efficient BONCAT-based approach will be valuable in monitoring the increase and spread of antibiotic resistance within natural and engineered aquatic environments.
10.1021/acs.est.2c05024
Unexpected lucidity in dementia: application of qualitative methods to develop an informant-reported lucidity measure.
Aging & mental health
OBJECTIVES:Unexpected lucidity is a phenomenon of scientific, clinical, and psychological relevance to health professionals, to those who experience it, and their relatives. This paper describes qualitative methods used to develop an informant-based measure of lucidity episodes. METHODS:The approach was refinement of the operationalization of the construct; review of seminal items, modification, and purification; and confirmation of the feasibility of reporting methodology. Modified focus groups were conducted with 20 staff and 10 family members using a web-based survey. Themes included reaction when hearing the term; words that come to mind; description of and first reaction to referenced or observed 'lucidity' events. Semi-structured cognitive interviews were conducted with 10 health professionals working with older adults with cognitive impairment. Data were extracted from Qualtrics or Microsoft 365 Word® for analysis using NVivo. RESULTS:Conceptual issues, as well as issues regarding comprehension, interpretation, clarity, semantics, and standardization of definitions derived from an external advisory board, focus groups and cognitive interviews informed items' modification, and resulted in the final lucidity measure. CONCLUSIONS:An obstacle to understanding the mechanisms and estimating the prevalence of lucid events among individuals with dementia and other neurological conditions is the scarcity of reliable and valid measures. The substantive and varied data gathered from multiple methods including the collaborative work of an External Advisory Board, modified focus groups with staff and family caregivers, and structured cognitive interviews with health professionals were central in creating the revised version of the lucidity measure.
10.1080/13607863.2023.2207167
Selective identification of newly synthesized proteins in mammalian cells using bioorthogonal noncanonical amino acid tagging (BONCAT).
Dieterich Daniela C,Link A James,Graumann Johannes,Tirrell David A,Schuman Erin M
Proceedings of the National Academy of Sciences of the United States of America
In both normal and pathological states, cells respond rapidly to environmental cues by synthesizing new proteins. The selective identification of a newly synthesized proteome has been hindered by the basic fact that all proteins, new and old, share the same pool of amino acids and thus are chemically indistinguishable. We describe here a technology, based on the cotranslational introduction of azide groups into proteins and the chemoselective tagging of azide-labeled proteins with an alkyne affinity tag, to separate and identify, specifically, the newly synthesized proteins in mammalian cells. Incorporation of the azide-bearing amino acid azidohomoalanine is unbiased, not toxic, and does not increase protein degradation. As a first demonstration of the method, we report the selective purification and identification of 195 metabolically labeled proteins with multidimensional liquid chromatography in-line with tandem MS. Furthermore, in combination with leucine-based mass tagging, candidates were immediately validated as newly synthesized proteins. The identified proteins, synthesized in a 2-h window, possess a broad range of biochemical properties and span most functional gene ontology categories. This technology makes it possible to address the temporal and spatial characteristics of newly synthesized proteomes in any cell type.
10.1073/pnas.0601637103
Bio-Nanohybrid Cell Based Signal Amplification System for Electrochemical Sensing.
Analytical chemistry
A signal amplification system for electrochemical sensing was established by bio-nanohybrid cells (BNC) based on bacterial self-assembly and biomineralization. The BNC was constructed by partially encapsulating a MR-1 cell with the self-biomineralized iron sulfide nanoparticles. The iron sulfide nanoparticle encapsulated BNCs showed high transmembrane electron transfer efficiency and was explored as a superior redox cycling module. Impressively, by integrating this BNC redox cycling module into the electrochemical sensing system, the output signal was amplified over 260 times compared to that without the BNC module. Uniquely, with this BNC redox cycling system, ultrasensitive detection of riboflavin with an extremely low LOD of 0.2 nM was achieved. This work demonstrated the power of BNC in the area of biosensing and provided a new possibility for the design of a whole cell redox cycling based signal amplification system.
10.1021/acs.analchem.2c01384
Microglia-Mediated Neuroinflammation: A Potential Target for the Treatment of Cardiovascular Diseases.
Journal of inflammation research
Microglia are tissue-resident macrophages of the central nervous system (CNS). In the CNS, microglia play an important role in the monitoring and intervention of synaptic and neuron-level activities. Interventions targeting microglia have been shown to improve the prognosis of various neurological diseases. Recently, studies have observed the activation of microglia in different cardiovascular diseases. In addition, different approaches that regulate the activity of microglia have been shown to modulate the incidence and progression of cardiovascular diseases. The change in autonomic nervous system activity after neuroinflammation may be a potential intermediate link between microglia and cardiovascular diseases. Here, in this review, we will discuss recent updates on the regulatory role of microglia in hypertension, myocardial infarction and ischemia/reperfusion injury. We propose that microglia serve as neuroimmune modulators and potential targets for cardiovascular diseases.
10.2147/JIR.S350109
Thailandepsin a.
Acta crystallographica. Section E, Structure reports online
THAILANDEPSIN A [SYSTEMATIC NAME: (E)-(1S,5S,6R,9S,20R)-6-[(2S)-butan-2-yl]-5-hy-droxy-20-[2-(meth-yl-sulfan-yl)eth-yl]-2-oxa-11,12-dithia-7,19,22-triaza-bicyclo-[7.7.6]docosa-15-ene-3,8,18,21-tetra-one], C(23)H(37)N(3)O(6)S(3), is a newly reported [Wang et al. (2011). J. Nat. Prod. doi:10.1021/np200324x] bicyclic depsipeptide that has potent histone deacetyl-ase inhibitory activity and broad-spectrum anti-proliferative activity. The absolute configuration of thailandepsin A has been determined from the anomalous dispersion and the stereochemistry of all chiral C atoms. Intra-molecular N-H⋯O and N-H⋯S hydrogen bonds occur. Inter-molecular N-H⋯O and O-H⋯O hydrogen bonds are observed in the crystal structure.
10.1107/S1600536811041390
Retraction.
International journal of cancer
Iwase M, Watanabe H, Kondo G, Ohashi M, Nagumo M. Enhanced susceptibility of oral squamous cell carcinoma cell lines to FAS-mediated apoptosis by cisplatin and 5-fluorouracil. Int J Cancer. 2003 Sep 10;106(4):619-25. doi:10.1002/ijc.11239 The above article, published online on May 30, 2003, in Wiley Online Library (https://onlinelibrary.wiley.com/doi/10.1002/ijc.11239), has been retracted by agreement between the journal Editor-in-Chief (Prof. Christoph Plass), the authors, and Wiley Periodicals LLC. An Expression of Concern (https://onlinelibrary.wiley.com/doi/10.1002/ijc.33825) was published during an earlier stage of this investigation. The retraction has been agreed following internal analyses and an investigation by the author's institution. The investigation concluded that data fabrication had taken place during compilation of the figures and that the manuscript was submitted without approval of the co-authors. As a result, the overall conclusions of this manuscript are considered invalid.
10.1002/ijc.34482