Fluorescence Study of Protein 3D Subdomains at the Nanoscale Level

2007 ◽  
Author(s):  
Tuan Vo-Dinh ◽  
Pierre Viallet
Keyword(s):  
Fluorescence Study ◽  
Nanoscale Level

Thieno[2,3-d]pyrimidin-4(3H)-one Derivatives of Benzimidazole as Potential Anti-Breast Cancer (MDA-MB-231, MCF-7) Agents.

2020 ◽  
Vol 20 ◽  
Author(s):  
Stefan Dimov ◽  
Anelia Ts. Mavrova ◽  
Denitsa Yancheva ◽  
Biliana Nikolova ◽  
Iana Tsoneva
Keyword(s):  
Breast Cancer ◽  
Cell Lines ◽  
Mechanism Of Action ◽  
Biologically Active ◽  
Breast Cancer Cell Lines ◽  
3T3 Cells ◽  
Fluorescence Study ◽  
Compound 21 ◽  
Mutational Activation ◽  
Mcf 7

Aims: The purpose was the synthesis of some new thienopyrimidines derivative of 1,3-disubstituted benzimidazoles and the evaluation of their cytotoxicity towards MDA-MB-231 and MCF-7 cell lines as well 3T3 cells. Background: An overexpression or mutational activation of TK receptors EGFR and HER2/neu are characteristic for tumors. It has been found that some thieno[2,3-d]pyrimidines exhibit better inhibitory activity against epidermal growth factor receptor (EGFR/ErbB-2) tyrosine kinase in comparison to aminoquinazolines. Breast cancer activity towards MDAMB-231 and MCF-7 cell lines by inhibiting EGFR was revealed by a novel 2-arylbenzimidazole. This motivated the synthesis of new thienopyrimidines possessing benzimidazole fragment in order to evaluate their cytotoxicity to the above mentioned cell lines. Objective: The objectives were the design and synthesis of a novel series thieno[2,3-d]pyrimidines bearing biologically active moieties as 1,3-disubstituted-benzimidazole heterocycle structurally similar to diaryl ureas in order to evaluate their cytotoxicity against MDA-MB-231, MCF-7 breast cancer cell lines. Methods: N,N-disubstituted benzimidazole-2-one carbonitriles were synthesized by Aza-Michael addition and used as precursors to generate some of the new thieno[2,3-d]pyrimidines in acidic medium. The interaction of chloroethyl-2- thienopyrimidines and 2-amino-benzimidazole resp. benzimidazol-2-one nitriles under solid-liquid transfer catalysis conditions lead to obtaining of new thienopyrimidines. MTT assay for cells survival was performed in order to establish the cytotoxicity of the tested compounds. Fluorescence study was used to elucidate some aspect of mechanism. Results: The effect of nine of the synthesized compounds was investigated towards MDA-MB-231 and MCF-7 cells as well as to 3T3 cells. Thieno[2,3-d]pyirimidine-4-one 16 (IC50 – 0.058 μM) and 21 (IC50 – 0.029 μM) possess high cytotoxicity against MDA-MB-231 cells after 24h. The most toxic against breast cancer MCF-7 cells was compounds 21 (IC50 – 0.074 μM), revealing lower cytotoxicity towards mouse fibroblast 3T3 cells with IC50 – 0.20 μM. SAR analisys was performed. Fluorescence study of the treatment of MDA-MB cells with compound 21 was carried out in order to clarify some aspects of mechanism of action. Conclusion: The relationship between cytotoxicity of compounds 14 and 20 against MCF-7 and 3T3 cells can suggest a similar mechanism of action. The antitumor potential of the tested compounds proves the necessity for further investigation to estimate the exact inhibition pathway in the cellular processes. The fluorescence study of the treatment of MDA-MB cells with compound 21 showed a rapid process of apoptosis.

scholarly journals Atomic force microscopy analysis of native infectious and inactivated SARS-CoV-2 virions

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sébastien Lyonnais ◽  
Mathilde Hénaut ◽  
Aymeric Neyret ◽  
Peggy Merida ◽  
Chantal Cazevieille ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Native Conformation ◽  
Force Microscopy ◽  
Enveloped Virus ◽  
Atomic Force ◽  
Afm Imaging ◽  
Level 3 ◽  
Microscopy Analysis ◽  
Virus Morphology ◽  
Nanoscale Level

AbstractSARS-CoV-2 is an enveloped virus responsible for the Coronavirus Disease 2019 (COVID-19) pandemic. Here, single viruses were analyzed by atomic force microscopy (AFM) operating directly in a level 3 biosafety (BSL3) facility, which appeared as a fast and powerful method to assess at the nanoscale level and in 3D infectious virus morphology in its native conformation, or upon inactivation treatments. AFM imaging reveals structurally intact infectious and inactivated SARS-CoV-2 upon low concentration of formaldehyde treatment. This protocol combining AFM and plaque assays allows the preparation of intact inactivated SARS-CoV-2 particles for safe use of samples out of level 3 laboratory to accelerate researches against the COVID-19 pandemic. Overall, we illustrate how adapted BSL3-AFM is a remarkable toolbox for rapid and direct virus analysis based on nanoscale morphology.

scholarly journals Unc13A and Unc13B contribute to the decoding of distinct sensory information in Drosophila

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Atefeh Pooryasin ◽  
Marta Maglione ◽  
Marco Schubert ◽  
Tanja Matkovic-Rachid ◽  
Sayed-mohammad Hasheminasab ◽  
...  
Keyword(s):  
Sensory Information ◽  
Projection Neuron ◽  
Physical Distance ◽  
Neural Decoding ◽  
Short Term ◽  
Short Term Plasticity ◽  
Appetitive Stimuli ◽  
Excitatory Projection ◽  
Direct Genetic Evidence ◽  
Nanoscale Level

AbstractThe physical distance between presynaptic Ca2+ channels and the Ca2+ sensors triggering the release of neurotransmitter-containing vesicles regulates short-term plasticity (STP). While STP is highly diversified across synapse types, the computational and behavioral relevance of this diversity remains unclear. In the Drosophila brain, at nanoscale level, we can distinguish distinct coupling distances between Ca2+ channels and the (m)unc13 family priming factors, Unc13A and Unc13B. Importantly, coupling distance defines release components with distinct STP characteristics. Here, we show that while Unc13A and Unc13B both contribute to synaptic signalling, they play distinct roles in neural decoding of olfactory information at excitatory projection neuron (ePN) output synapses. Unc13A clusters closer to Ca2+ channels than Unc13B, specifically promoting fast phasic signal transfer. Reduction of Unc13A in ePNs attenuates responses to both aversive and appetitive stimuli, while reduction of Unc13B provokes a general shift towards appetitive values. Collectively, we provide direct genetic evidence that release components of distinct nanoscopic coupling distances differentially control STP to play distinct roles in neural decoding of sensory information.

scholarly journals Novel Approach to Tooth Chemistry: Quantification of Human Enamel Apatite in Context for New Biomaterials and Nanomaterials Development

2020 ◽  
Vol 22 (1) ◽  
pp. 279
Author(s):  
Andrzej Kuczumow ◽  
Renata Chałas ◽  
Jakub Nowak ◽  
Wojciech Smułek ◽  
Maciej Jarzębski
Keyword(s):  
Biomedical Applications ◽  
Energy Levels ◽  
New Class ◽  
Novel Approach ◽  
Human Enamel ◽  
Linear Profiles ◽  
Resistant Form ◽  
Molar Teeth ◽  
Stable Core ◽  
Nanoscale Level

A series of linear profiles of the elements of the enamel in human molar teeth were made with the use of an electron microprobe and a Raman microscope. It is postulated that the enamel can be treated as the superposition of variable “overbuilt” enamel on the stable “core” enamel at the macro-, micro- and nanoscale level. The excessive values characterize the “overbuilt enamel”. All the profiles of excessive parameters along the enamel thickness from the enamel surface to the dentin enamel junction (DEJ) can be approximated very precisely with the use of exponential functions, where Ca, P, Cl and F spatial profiles are decaying while Mg, Na, K and CO32− ones are growing distributions. The “overbuilt” apatite formed on the boundary with DEJ, enriched in Na, Mg, OH and carbonates, reacts continuously with Ca, Cl and F, passing into an acid-resistant form of the “overbuilt” enamel. The apparent phases arriving in boundary regions of the “overbuilt enamel” were proposed. Microdiffraction measurements reveal relative variation of energy levels during enamel transformations. Our investigations are the milestones for a further new class of biomaterial and nanomaterial development for biomedical applications.

Interaction of ectoine and hydroxyectoine with protein: fluorescence study

2021 ◽  
Author(s):  
Auguste Rasteniene ◽  
Ruta Gruskiene ◽  
Jolanta Sereikaite
Keyword(s):  
Protein Fluorescence ◽  
Fluorescence Study
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