LIM kinase/inhibitor binding study in cell lysates using microscale thermophoresis in the red spectrum

International audienceBackground: Cellular function depends on complex molecular interactions that activate signaling pathways - central to drug discovery projects. LIM kinases (LIMKs) are attractive therapeutic targets implicated in various diseases, yet no clinically approved LIMK inhibitors exist, likely due to limited understanding of their molecular behavior under near-physiological conditions. This breach stems in part from the difficulty in purifying these proteins. To address this, there is a crucial need for a simple and rapid method to determine LIMK-inhibitor binding affinities (Kd values) directly in cell lysates, bypassing challenging purification and immobilization steps.Results: The monomeric near-infrared fluorescent protein miRFP670 (excitation/emission: 640/680 nm) is an advantageous fluorescent tag for microscale thermophoresis (MST) assays in cell lysates. The miRFP670-tagged LIMKs were successfully overexpressed in HEK293 cells, characterized, and validated by western blotting. MST assay conditions - including MST buffer composition and target storage - were carefully optimized and negative controls were consistently used to ensure data reproducibility as well as assay specificity. The MST conditions were as follows: miRFP670-kinases at a fixed concentration of a few tens of nM in cell lysate supplemented with 30 % (v/v) glycerol for convenient storage; 0.005 % (v/v) DMSO in the MST buffer; 37 ◦C; 20 % LED power; medium MST power; and standard capillaries. The presence of 0.1 % Triton X-100 in the MST buffer was essential to prevent protein aggregation, as evidenced by smooth MST time traces. The reproducibility and stability of signals across all capillaries attest to the optimality of the incubation conditions and the attainment of a stable binding equilibrium. This consistency also validates the robustness of the assay. MST analysis of cell lysates yielded Kd values for full-length and kinase domains and show strong agreement with literature where available. Notably, sub-micromolar Kd values were confirmed for the reference inhibitors LX7101, BMS-5, and TH-257, with slight differences observed between full-length LIMKs and their kinase domains - differences often overlooked in the literature.Significance and novelty: This work establishes the first detailed production, characterization, and use of miRFP670 in MST-based evaluation of biomolecular interactions under near-native conditions. miRFP670 operates in a spectral region (red) with minimal cellular autofluorescence, enhancing signal specificity and sensitivity. This approach offers a straightforward and broadly applicable, purification-free platform for early-stage drug discovery

Bronze, pierre(s) et parchemin. Fama et exemplarité dans Le Livre de la Cité des dames de Christine de Pizan

International audienceWhich authority decides to make an exemplum exemplary and ensures its fama, in Christine de Pizan's Le Livre de la Cité des Dames? If the bronze statue that the public authority erects to Clélie shows her exemplarity, the texts are more reliable in ensuring the lasting of the fama: Christine modifies the value of the exemplum of Lucretia's suicide. She builds on parchment the City of stones, populated by women who are"good examples", and thus builds her own reputation as an exemplary writer.Nous nous demanderons quelle autorité décide de rendre un exemplum exemplaire et assure sa fama, dans La Cité des dames de Christine de Pizan. Si la statue de bronze que l’autorité publique élève à Clélie signale son exemplarité, les textes sont plus durables pour assurer la pérennité de la fama : Christine, en reprenant le suicide de Lucrèce modifie la valeur de l’exemplum. Elle bâtit sur parchemin la Cité de pierres, peuplée de femmes « bons exemples », et se construit ainsi une renommée d’écrivaine exemplaire

Technological trajectories in iron smelting: slag signatures, recipes, and traditions from Phnom Dek (Cambodia, 7th–20th c. CE)

International audienceThis study investigates the long-term dynamics of bloomery iron smelting practices across the Phnom Dek region of Cambodia, a major metallurgical landscape active from at least the 7th to 20th centuries CE. Based on pXRF analysis of more than 1,700 slag samples, it develops an interpretive framework that integrates multiple scales of evidence, combining chemical composition, spatial distribution, technical features, and chronological context. At the core of this approach is the identification of coherent chemical signatures in slag, which, by using multivariate analyses, function as proxies for metallurgical recipes, and, at a broader level, enduring technological traditions shaped by the social organization of production. These signatures serve as comparative units for tracing production behaviors across sites and time periods. Through the categories of practice and recipe, the analysis aims to identify patterns of continuity, adaptation, and transformation in iron-making processes or smelting behavior over time. Results point to significant changes in ore procurement and recipe during the 11th–12th centuries, likely linked to wider transformations within Angkorian state dynamics. The persistence of specific chemical profiles and regionally shared smelting practices beyond this period suggests a bloomery tradition sustained across the landscape. Ultimately, the study argues that the chemistry of slag, as a material trace of smelting activities derived from technical, spatial, and chronological contexts, has unique capabilities to acquire interpretive significance when analyzed across these dimensions. This approach enables the discussion of technological trajectories in iron production and the socio-technical logics that shaped the evolution of the Phnom Dek metallurgical landscape

Combustion of NH3/CH4 mixtures in a swirl burner: Study of non-premixed flames with radial fuel injection

International audienceThe transition to renewable energy is essential in addressing climate change. While natural gas plays a significant role in this transition, it still produces CO2 emissions. Ammonia (NH3) is being investigated as a promising alternative fuel. However, ammonia combustion presents several technical challenges, such as low flame velocity, limited calorific value, difficulties with flame stabilization, and high NOx emissions. This study examines the impact of ammonia addition to methane, equivalence ratio, and swirl number on pollutant emissions (NO, CO, CH4, and CO2), exhaust gas temperature, and flame stability. Experiments are carried out using a swirl burner with a radial fuel injection in a 1-meter high combustion chamber. The burner consists of two concentric tubes, with the inner tube supplying fuel and the outer tube supplying air. The fuel is injected radially through eight holes at the burner exit. The ammonia fraction ranges from 0 to 100 %, the equivalence ratio from 0.8 to 1.0, and the swirl number from 0.8 to 1.4, with a constant flame power of 10 kW. Emissions of NO, CO, CH4, and CO2 are measured in the dry exhaust gases using a multi-gas analyzer, inside chamber temperatures are measured and the flame structure is analyzed via OH* and NH2* chemiluminescence and velocity measurements by LDA technique. The results show that both the swirl number and equivalence ratio significantly alter flame geometry, affecting combustion zones and flame height. Axial velocity measurements indicate that the recirculation zone shrinks with ammonia addition, while a high swirl number increases axial velocity, promoting ammonia combustion and upstream flame propagation. Up to 30 % ammonia, the flame remains stable, but higher ammonia levels lead to fluctuations in stabilization. High ammonia content in the fuel mixture results in reductions of NO, CO, and CO2 emissions, though there is a potential increase in unburned gases. As expected, the inside chamber temperatures decrease as the ammonia fraction increases

Le Miroir des sots de Nigel de Longchamps

International audienceFirst French translation, with commentary, of Nigel de Longchamps' (Wireker) work, Speculum Stultorum. A poem of 4000 elegiac lines, composed in Latin by this Anglo-Norman monk of the late 12th century, in which he makes, through the tribulations and encounters of the donkey Burnellus, a fierce satire of the papacy and the various religious orders of his time,Cet ouvrage propose la première traduction française, avec commentaires, de l'ouvrage de Nigel de Longchamps (Wireker), Speculum Stultorum. Il s'agit du poème de 4000 vers élégiaques, composé en latin par ce moine anglo-normand de la fin du XIIe siècle, dans lequel il fait, à travers les tribulations et les rencontres de l'âne Burnellus, une satire féroce de la papauté et es différents ordres religieux de son temps

Trésors cachés, louis exhibé : la monnaie comme objet théâtral chez Plaute et Molière

International audienceLa plume des dramaturges fait des deux trésors monétaires cachés par un avare des « objets théâtraux » (Martial Poirson), dans L’Aululaire de Plaute et L’Avare de Molière, en opposition avec le louis d’or exhibé par Dom Juan face au pauvre. L’analyse porte sur les fonctions multiples de ces monnaies : objet dramaturgique comme moteur de l’intrigue, transactionnel dans l’économie domestique, scénique selon sa place dans la scénographie, symbolique en tant qu’objectif ultime ou marque de pouvoi

Plasma jet and plasma treated aerosol induced permeation of reconstructed human epidermis

International audienceAs plasma-treated liquids have many applications in plasma medicine, their cutaneous effects for cosmetic purposes are also considered as an alternative way to treat skin without the electric hazards and limitations correlated with the use of a direct plasma. Our previous work on human skin explants showed increased transdermal diffusion of cosmetic ingredients (caffeine, hyaluronic acid) after direct plasma treatment. Despite this proven efficacy, these protocols still face limitations dealing with toxicity, small treatment areas and uneven surface coverage. To overcome these limitations and broaden the scope of non-thermal-plasma-based technology for skin care, this study presents for the first time the development and assessment of a plasma aerosol device to nebulize plasma-treated liquids on skin model

Blind test sur les musiques de fête, ouverture du festival d'histoire populaire de Créteil

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Fusion Protein‐Assisted Crystallization of Human SUMO1

International audienceABSTRACT In this study, we employed a fusion protein‐assisted approach to crystallize human SUMO1, an essential covalent protein modifier that also interacts noncovalently with specific linear protein motifs called SUMO‐interacting motifs (SIMs). SUMO1 has been crystallized previously as part of various complexes but never in isolation. Our strategy involved fusing a variant of a known crystallization facilitator, the TELSAM domain, upstream of the folded part of the SUMO1 protein (residues 18–97). Following a simple purification strategy, we obtained a 2.05‐Å crystal structure of apo TELSAM‐SUMO1, with three distinct SUMO1 chains per asymmetric unit, two of which have an accessible pocket for binding to a SIM. The crystal structure is composed of the expected left‐handed helical filaments formed by TELSAM domains, with protruding SUMO1 molecules mediating connections within and between these filaments to stabilize a three‐dimensional lattice. Since the TELSAM fusion does not affect the SUMO:SIM interaction, as confirmed in solution, our construct may potentially be used to structurally characterize complexes formed between SUMO and SIM‐containing peptides. Neither does the TELSAM fusion interfere with the attachment of SUMO1 to substrates, potentially allowing for the creation of SUMOylated protein forms with improved crystallizability. The study represents a novel application of TELSAM‐assisted crystallization to a small protein of major biological relevance

Bivariate P -and Q-polynomial structures of the association schemes based on attenuated spaces

International audienceThe bivariate P -and Q-polynomial structures of association schemes based on attenuated spaces are examined using recurrence and difference relations of the bivariate polynomials which form the eigenvalues of the scheme. These bispectral properties are obtained from contiguity relations of univariate dual q-Hahn and affine q-Krawtchouk polynomials. The bispectral algebra associated to the bivariate polynomials is investigated, as well as the subconstituent algebra of the schemes. The properties of the schemes are compared to those of the non-binary Johnson schemes through a limit