Abstract: The invention relates to a compound characterized by general formula (100), wherein R1 and R6 are H or F, R2, R3, R4 and R5 can be any substituent, R7, R8, RN1, RN2, RN3 and RN4 are a hydrocarbon moiety, one of R9 and R10 is hydrogen and the other one is hydrogen or a saturated carbon atom connected to any substituent, and its use in staining and live cell fluorescence imaging.

Abstract: A first aspect of the invention relates to a non-covalently-HaloTag-binding compound characterized by the general formula D-L-T (I), wherein D is or comprises a functional moiety Z, particularly a fluorescent dye, or D is a linkable moiety (i.e. a moiety that can be coupled to other functional groups), L is a linear linker of 10-15 atoms in length, and T is a moiety selected from the group comprising methylamine, methylsulfonamide, acetamide, or their respective fluorinated analogues, azide, or hydroxyl. Another aspect of the invention relates to a HaloTag variant wherein position D106 of the HaloTag7 sequence is exchanged for a proteinogenic amino acid different from D. The variant has a different binding specificity for HaloTag substrates compared to the non-variant Halotag polypeptide. Yet another aspect of the invention relates to kits comprising polypeptides or nucleic acids and the non-covalently-HaloTag-binding compound according to the invention.

Abstract: The invention relates to a compound characterized by general formula (100), wherein R1 and R6 are H or F, R2, R3, R4 and R5 can be any substituent, R7, R8, RN1, RN2, RN3 and RN4 are a hydrocarbon moiety, one of R9 and R10 is hydrogen and the other one is hydrogen or a saturated carbon atom connected to any substituent, and its use in staining and live cell fluorescence imaging.

Abstract: The present invention relates to rhodamine-type fluorophores being present in two states, a cell-permeable non-florescent form and a fluorescent form. The present invention also relates to use of the fluorophores in staining and live cell fluorescence imaging. The compounds have general formula (10) or the general formula (10?).

Abstract: The invention relates to a modular polypeptide comprising a first partial effector sequence comprising a first part of a circular permutated halotag protein connected to a sensor module sequence, which is connected to a second part of a circular permutated halotag protein. The sensor module is a single polypeptide or a polypeptide pair capable of undergoing conformational change from a first confirmation to a second confirmation depending on the presence or concentration of an analyte compound. The modular peptide is catalytically active in response to an environmental stimulus or in response to the sensor pair interacting. The invention further relates to nucleic acid sequences encoding the modular polypeptide, and to kits comprising same.

Abstract: The invention pertains to a near-infrared fluorescent dye that is cell permeable and can be attached to selected proteins in living cells. The dye has the general formula or its corresponding spirolactone wherein Y is chosen from the group consisting of Si, Ge and Sn; R0 is —COO? or COOH; R1, R2, R3, R4, R5, R6, R7, R8, R9, R10, R11, R12, R13, R14, R15 and R16 are substituents, including hydrogen, independently from each other. The dye (i) absorbs and emits light at wavelengths above 600 nm; (ii) possesses high photostability; (iii) has high extinction coefficients and high quantum yields; (iv) can be derivatized with different molecules; and (v) is membrane-permeable and shows minimal background binding to biomolecules and biomolecular structures.

Abstract: The invention pertains to a near-infrared fluorescent dye that is cell permeable and can be attached to selected proteins in living cells. The dye has the general formula or its corresponding spiro ac one wherein Y is chosen from the group consisting of Si, Ge and Sn; R0 is —COO? or COOH; R1, R2, R3, R4, R5, R6, R7, R8, R9, R10, R11, R12, R13, R15 and R16 are substituents, including hydrogen, independently from each other. The dye (i) absorbs and emits light at wavelengths above 600 nm; (ii) possesses high photostability; (iii) has high extinction coefficients and high quantum yields; (iv) can be derivatized with different molecules; and (v) is membrane-permeable and shows minimal background binding to biomolecules and biomolecular structures.

Abstract: The invention pertains to a near-infrared fluorescent dye that is cell permeable and can be attached to selected proteins in living cells. The dye has the general formula or its corresponding spirolactone wherein Y is chosen from the group consisting of Si, Ge and Sn; R0 is —COO? or COOH; R1, R2, R3, R4, R5, R6, R7, R8, R9, R10, R11, R12, R13, R14, R15 and R16 are substituents, including hydrogen, independently from each other. The dye (i) absorbs and emits light at wavelengths above 600 nm; (ii) possesses high photostability; (iii) has high extinction coefficients and high quantum yields; (iv) can be derivatized with different molecules; and (v) is membrane-permeable and shows minimal background binding to biomolecules and biomolecular structures.

Abstract: The invention pertains to a near-infrared fluorescent dye that is cell permeable and can be attached to selected proteins in living cells. The dye has the general formula or its corresponding spirolactone wherein Y is chosen from the group consisting of Si, Ge and Sn; R0 is —COO? or COOH; R1, R2, R3, R4, R5, R6, R7, R8, R9, R10, R11, R12, R13, R14, R15 and R16 are substituents, including hydrogen, independently from each other. The dye (i) absorbs and emits light at wavelengths above 600 nm; (ii) possesses high photostability; (iii) has high extinction coefficients and high quantum yields; (iv) can be derivatized with different molecules; and (v) is membrane-permeable and shows minimal background binding to biomolecules and biomolecular structures.

Abstract: The invention relates to new proteins called alkylcytosine transferases (ACTs) derived from O6-alkylguanine-DNA alkyltransferase, and to substrates for ACTs specifically transferring a label to these ACTs and to fusion proteins comprising these. The substrates according of the invention are substituted cytosines of formula (I) wherein R1 is an aromatic or a heteroaromatic group, or an optionally substituted unsaturated alkyl, cycloalkyl or heterocyclyl group with the double bond connected to OCH2—; R2 is a linker; and L is a label or a plurality of same or different labels. The invention further relates to methods of transferring label L from these substrates of formula (I) to ACTs and ACT fusion proteins. The system of ACT-compound of formula (I) is particularly suitable for double labelling studies together with the known system O6-alkylguanine-DNA alkyltransferase (AGT)-benzylguanines.

Abstract: A method for labeling acyl carrier protein (ACP) fusion proteins with a wide variety of different labels is disclosed. The method relies on the transfer of a label from a coenzyme A type substrate to an ACP fusion protein using a holo-acyl carrier protein synthase (ACPS) or a homologue thereof. The method allows detecting and manipulating the fusion protein, both in vitro and in vivo, by attaching molecules to the fusion proteins that introduce a new physical or chemical property to the fusion protein. Examples of such labels are, among others, spectroscopic probes or reporter molecules, affinity tags, molecules generating reactive radicals, cross-linkers, ligands mediating protein-protein interactions or molecules suitable for the immobilization of the fusion protein.

Abstract: A method of using O6-alkylguanine-DNA alkyltransferase (AGT) is disclosed for transferring a label from a substrate to a fusion protein comprising the AGT. This allows the detection and/or manipulating of the fusion protein, both in vitro and in vivo, by attaching molecules to the fusion proteins that introduce a new physical or chemical property to the fusion protein. Examples of such molecules are, among others, spectroscopic probes or reporter molecules, affinity tags, molecules generating reactive radicals, cross-linkers, ligands mediating protein-protein interactions or molecules suitable for the immobilisation of the fusion protein.

Abstract: The invention relates to new proteins called alkylcytosine transferases (ACTs) derived from O6-alkylguanine-DNA alkyltransferase, and to substrates for ACTs specifically transferring a label to these ACTs and to fusion proteins comprising these. The substrates according of the invention are substituted cytosines of formula (I) wherein R1 is an aromatic or a heteroaromatic group, or an optionally substituted unsaturated alkyl, cycloalkyl or heterocyclyl group with the double bond connected to OCH2—; R2 is a linker; and L is a label or a plurality of same or different labels. The invention further relates to methods of transferring label L from these substrates of formula (I) to ACTs and ACT fusion proteins. The system of ACT-compound of formula (I) is particularly suitable for double labelling studies together with the known system O6-alkylguanine-DNA alkyltransferase (AGT)-benzylguanines.

Abstract: The invention relates to new proteins called alkylcytosine transferases (ACTs) derived from O6-alkylguanine-DNA alkyltransferase, and to substrates for ACTs specifically transferring a label to these ACTs and to fusion proteins comprising these. The substrates according of the invention are substituted cytosines of formula (I) wherein R1 is an aromatic or a heteroaromatic group, or an optionally substituted unsaturated alkyl, cycloalkyl or heterocyclyl group with the double bond connected to OCH2—; R2 is a linker; and L is a label or a plurality of same or different labels. The invention further relates to methods of transferring label L from these substrates of formula (I) to ACTs and ACT fusion proteins. The system of ACT-compound of formula (I) is particularly suitable for double labelling studies together with the known system O6-alkylguanine-DNA alkyltransferase (AGT)-benzylguanines.

Abstract: The invention relates to substrates for O6-alkylguanine-DNA alkyltransferases (AGT) of formula R1-A-X—CH2—R3—R4-L1, wherein A is a group recognized by AGT as a substrate, X is oxygen or sulfur, R1 is a group —R2-L2 or a group R5, R2 and R4 are, independently of each other, a linker, R3 is an aromatic or a heteroaromatic group, or an optionally substituted unsaturated alkyl, cycloalkyl or heterocyclyl group with the double bond connected to CH2, R5 is arylmethyl or heteroarylmethyl or an optionally substituted cycloalkyl, cycloalkenyl or heterocyclyl group, L1 is a label, a plurality of same or different labels, a bond connecting R4 to A forming a cyclic substrate, or a further group —R3—CH2—X-A-R1, and L2 is a label or a plurality of same or different labels. The invention further relates to methods of transferring a label from these substrates to O6-alkylguanine-DNA alkyltransferases (AGT) and AGT fusion proteins.

Abstract: The invention relates to new proteins called alkylcytosine transferases (ACTs) derived from O6-alkylguanine-DNA alkyltransferase, and to substrates for ACTs specifically transferring a label to these ACTs and to fusion proteins comprising these. The substrates according of the invention are substituted cytosines of formula (I) wherein R1 is an aromatic or a heteroaromatic group, or an optionally substituted unsaturated alkyl, cycloalkyl or heterocyclyl group with the double bond connected to OCH2—; R2 is a linker; and L is a label or a plurality of same or different labels. The invention further relates to methods of transferring label L from these substrates of formula (I) to ACTs and ACT fusion proteins. The system of ACT-compound of formula (I) is particularly suitable for double labelling studies together with the known system O6-alkylguanine-DNA alkyltransferase (AGT)-benzylguanines.

Abstract: A method of using O6-alkylguanine-DNA alkyltransferase (AGT) is disclosed for transferring a label from a substrate to a fusion protein comprising the AGT. This allows the detection and/or manipulating of the fusion protein, both in vitro and in vivo, by attaching molecules to the fusion proteins that introduce a new physical or chemical property to the fusion protein. Examples of such molecules are, among others, spectroscopic probes or reporter molecules, affinity tags, molecules generating reactive radicals, cross-linkers, ligands mediating protein-protein interactions or molecules suitable for the immobilisation of the fusion protein.

Abstract: The invention relates to AGT mutants showing, when compared to the wild type human AGT, two or more advantageous properties selected from (a) reduced DNA interaction; (b) localisation of the expressed protein in eukaryotic cells that is no longer restricted to the nucleus; (c) improved expression yield as soluble protein and improved stability in various hosts; (d) improved stability under oxidising conditions; (e) improved stability within cells after reaction with a substrate; (f) improved stability outside cells before and after reaction with a substrate; (g) improved in vitro solubility; (h) improved reactivity against O6-alkylguanine substrates; (i) reduced reactivity against DNA-based substrates; and (j) reduced reactivity against N9-substituted O6-alkylguanine substrates.

Abstract: A method using O6-alkylguanine-DNA alkyltransferases (AGT) is disclosed for transferring a label from a substrate to a fusion protein comprising the AGT. This allows the detection and/or manipulating of the fusion protein, both in vitro and in vivo, by attaching molecules to the fusion proteins that introduce a new physical or chemical property to the fusion protein. Examples of such molecules are, among others, spectroscopic probes or reporter molecules, affinity tags, molecules generating reactive radicals, cross-linkers, ligands mediating protein-protein interactions or molecules suitable for the immobilisation of the fusion protein.

Abstract: The invention relates to AGT mutants showing, when compared to the wild type human AGT, two or more advantageous properties selected from (a) reduced DNA interaction; (b) localisation of the expressed protein in eukaryotic cells that is no longer restricted to the nucleus; (c) improved expression yield as soluble protein and improved stability in various hosts; (d) improved stability under oxidising conditions; (e) improved stability within cells after reaction with a substrate; (f) improved stability outside cells before and after reaction with a substrate; (g) improved in vitro solubility; (h) improved reactivity against O6-alkylguanine substrates; (1) reduced reactivity against DNA-based substrates; and (j) reduced reactivity against N9-substituted O6-alkylguanine substrates.