Abstract: The invention relates to a novel method for determining the binding of an antibody to the complement component 1q (C1q). The process according to the invention makes it possible to measure the binding of an antibody to the C1q in a Homogeneous Proximity Assay (HAS).

Abstract: The invention relates to antibodies or antibody fragments capable of binding to G-protein alpha, nucleic acid sequences coding for the antibody, vectors comprising the nucleic acid sequence, cells comprising the vector or the nucleic acid sequence and a kit-of-parts comprising (i) the antibody or antibody fragment or the composition and (ii) a source of GTP labeled with a member of a pair of RET partners.

Abstract: The invention relates to compounds of formula: in which X, Y, L and Ln3+ are as defined in the description.

Abstract: The invention relates to a method for determining the ability of a molecule to modulate the activation of a G protein-coupled receptor (GPCR), said method comprising the following steps: a) introducing, in a first container: a membrane preparation bearing one or more GPCRs and one or more alpha G-proteins, a source of nonhydrolyzable or slowly hydrolyzable GTP labeled with a first member of a pair of RET partners, a ligand of the alpha subunit of a G protein (alpha G-protein) labeled with a second member of the pair of RET partners, said ligand being capable of binding to the full alpha G-protein bound to the nonhydrolyzable or slowly hydrolyzable GTP labeled with the first member of a pair of RET partners, optionally a GPCR agonist; b) measuring the RET signal emitted in the first container; c) introducing (i) in a second container, the same reagents as in step a) and the molecule to be assayed or (ii) in the first container, the molecule to be assayed; d) measuring the RET signal emitted in the second

Abstract: The invention relates to compounds of formula (I?): in which A, L2, M and B are as defined in the description. These compounds are substrates of O6-alkylguanine-DNA alkyltransferase and mutants thereof.

Abstract: The instant invention provides for methods for detecting the internalization of a transmembrane protein of interest expressed at the surface of a cell. More specifically, the methods involve (a) labelling the protein of interest with a fluorescent metal complex, the lifetime of which is greater than 0.1 ms, (b) adding to the reaction medium a composition capable of causing the internalization of the protein of interest, (c) adding to the reaction medium (1) a modulating agent which is a fluorescent FRET acceptor compound compatible with the fluorescent metal complex, the final concentration of which in the reaction medium is greater than 10?7M; or (2) a reducing agent, the redox potential of which is less than +0.1 V and preferably between 0.25 and 0.

Abstract: The invention relates to a method for determining whether a test compound binds preferentially to a membrane receptor R1 or to a membrane receptor R2, these receptors being known to be expressed on the surface of the cells in monomeric, homodimeric or heterodimeric form. This method is applied using one or two FRET partner pairs.

Abstract: The invention relates to a method for selecting compounds having a modulating effect on the activation state of a dimer of VFT-domain proteins expressed in cell membranes present in a measuring medium, said dimer consisting of a first protein and of a second protein, said proteins being identical or different, wherein this method comprises the following steps: (a) labeling the first and second proteins in the N-terminal portion of their VFT domains with the members of a pair of FRET partners, the Förster radius (R0) of said pair being between 20 and 55 ?; (b) measuring the FRET signal in the absence and in the presence of the test compound within a predetermined time window; (c) selecting the test compound as a modulating compound if a difference in FRET signal in the absence and in the presence of test compound is measured in step (b). The invention can be used in the search for new medicaments and new taste modulators.

Abstract: Method for the detection in homogeneous medium of a post-translational modification of a proteinaceous substrate catalyzed by a cell enzyme, characterized in that the post-translational modification reaction takes place in intact living cells, in that these cells comprise a heterologous expression vector coding for a fusion protein comprising the proteinaceous substrate and a first coupling domain and in that it comprises the following stages: (i) Incubation of the cells in the presence or in the absence of a compound to be tested capable of modulating the activity of said enzyme, (ii) Addition to the reaction medium of a first fluorescent compound member of a first pair of FRET partners covalently bonded to a coupling agent capable of binding specifically to the first coupling domain present on the proteinaceous substrate, (iii) Addition to the reaction medium of a second fluorescent compound member of this first pair of FRET partners, and covalently bonded to a binding domain specific to the site of the

Abstract: The invention relates to a quantitative non-microscopic method of detecting intracellular interactions between biomolecules in living cells, in response to a biological or pharmacological stimulation, by a time-resolved proximate energy transfer effect between two members of a fluorescence donor/acceptor pair.

Abstract: The invention relates to a method for suppressing the FRET emitted by a reaction medium containing a pair of fluorescent FRET partner conjugates specific for a biological event, characterized in that a FRET signal killer which does not disturb said biological event is introduced into this medium.

Abstract: The invention relates to a method for determining whether a test compound binds preferentially to a membrane receptor R1 or to a membrane receptor R2, these receptors being known to be expressed on the surface of the cells in monomeric, homodimeric or heterodimeric form. This method is applied using one or two FRET partner pairs.

Abstract: The present invention relates to inositol phosphate derivatives, in which the inositol phosphate is substituted with one or two reactive groups G or one or two conjugated substances or molecules M, said reactive group(s) G or said substance(s) or molecule(s) M being linked to IP1 via a linkage group L, M being chosen from the following group: a tracer, an immunogen, a member of a binding partner pair, a solid support. Application: tools allowing the study of the inositol phosphate cycle and therefore, indirectly, the study of seven transmembrane domain receptors coupled to phospholipase C, receptors having a tyrosine kinase activity, and in general enzymes involved in the variations of the intracellular concentration of IP1.

Abstract: The invention relates to a method for selecting compounds having a modulating effect on the activation state of a dimer of VFT-domain proteins expressed in cell membranes present in a measuring medium, said dimer consisting of a first protein and of a second protein, said proteins being identical or different, wherein this method comprises the following steps: (a) labeling the first and second proteins in the N-terminal portion of their VFT domains with the members of a pair of FRET partners, the Förster radius (R0) of said pair being between 20 and 55 ?; (b) measuring the FRET signal in the absence and in the presence of the test compound within a predetermined time window; (c) selecting the test compound as a modulating compound if a difference in FRET signal in the absence and in the presence of test compound is measured in step (b). The invention can be used in the search for new medicaments and new taste modulators.

Abstract: A method for detecting the internalization of a transmembrane protein of interest expressed at the surface of a cell, comprising the following steps: a) labelling the protein of interest with a fluorescent metal complex, the lifetime of which is greater than 0.1 ms; b) adding to the reaction medium a composition capable of causing the internalization of the protein of interest; c) adding to the reaction medium a modulating agent selected from: a. a fluorescent or nonfluorescent FRET acceptor compound compatible with said fluorescent metal complex, the final concentration of which in the reaction medium is greater than 10?7M; b. a reducing agent, the redox potential of which is less than +0.1 V and preferably between 0.25 and 0.75 V; c. an agent which binds specifically, by noncovalent bonding, with the fluorescent metal complex; d.

Abstract: The invention relates to compounds of formula (I?): in which A, L2, M and B are as defined in the description.

Abstract: The present invention relates to a method of revealing a biological process using a FRET measurement, which comprises the following steps: incorporating, into a measurement medium containing a lipid membrane, a biological entity X coupled with a first member of a pair of FRET partners and a second biological entity Y coupled with the second member of the pair of FRET partners, the energy-donating member of the pair of FRET partners having a long lifetime and the members of said pair of FRET partners being located on either side of the lipid membrane; exciting the measurement medium at the excitation wavelength of the energy-donating member; and measuring the FRET signal or the variations in said signal emitted in said culture medium.

Abstract: The invention concerns the use of the fluorescence polarization phenomenon to improve detection of fluorescent signals during a fluorescence resonance energy transfer (FRET). In particular, the invention concerns a method for improving signal/noise ratio in a FRET measurement. The invention also concerns an apparatus for measuring fluorescence following an energy transfer between a donor fluorescent compound and an acceptor fluorescence compound in a measurement medium.

Abstract: Method for the detection in homogeneous medium of a post-translational modification of a protein substrate catalyzed by a cell enzyme, characterized in that the post-translational modification reaction takes place in intact living cells, in that these cells comprise a heterologous expression vector coding for a fusion protein comprising the protein substrate and a first coupling domain and in that it comprises the following stages: (v) Incubation of the cells in the presence or in the absence of a compound to be tested capable of modulating the activity of said enzyme, (vi) Addition to the reaction medium of a first fluorescent compound member of a first pair of FRET partners covalently bonded to a coupling agent capable of binding specifically to the first coupling domain present on the protein substrate, (vii) Addition to the reaction medium of a second fluorescent compound member of this first pair of FRET partners, and covalently bonded to a binding domain specific to the site of the protein substrate hav

Abstract: The invention concerns the use of the fluorescence polarization phenomenon to improve detection of fluorescent signals during a fluorescence resonance energy transfer (FRET). In particular, the invention concerns a method for improving signal/noise ratio in a FRET measurement. The invention also concerns an apparatus for measuring fluorescence following an energy transfer between a donor fluorescent compound and an acceptor fluorescence compound in a measurement medium.