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Philippe Durand - One of the best experts on this subject based on the ideXlab platform.

  • topography of equine chorionic gonadotropin epitopes relative to the luteinizing Hormone and follicle stimulating Hormone Receptor Interaction sites
    Molecular and Cellular Endocrinology, 1993
    Co-Authors: M Chopineau, Yves Combarnous, Marie-christine Maurel, Philippe Durand
    Abstract:

    Abstract In order to localize the epitopes of equine chorionic gonadotropin (eCG) involved in Interaction with luteinizing Hormone (LH) and follicle-stimulating Hormone (FSH) Receptors, we used 14 monoclonal anti-eCG antibodies (mAbs). Different effects of these mAbs on the bioactivities of eCG were observed in in vitro bioassays, but the effects of each mAb on the two bioactivities were similar for all but four mAbs. All mAbs were found to inhibit the binding of eCG to LH Receptors except 3A3 mAb, in radioReceptor assay. Six mAbs, which were strong inhibitors of eCG binding to LH Receptors and of both bioactivities, recognized the same area on the α subunit of eCG. All others, except 3A3, recognized epitopes close to the former, and close to each other. 3A3 mAb had a hyperstimulatory effect on FSH bioactivity, and was the only mAb that did not inhibit binding. It appeared to recognize a different epitopic area. These observations suggest that there is a main antigenic area on eCG, which corresponds to the Interaction site of eCG with both Receptors. It mostly involves the α subunit and to a lesser extent the β subunit.

  • topography of equine chorionic gonadotropin epitopes relative to the luteinizing Hormone and follicle stimulating Hormone Receptor Interaction sites
    Molecular and Cellular Endocrinology, 1993
    Co-Authors: M Chopineau, Yves Combarnous, Marie-christine Maurel, Philippe Durand
    Abstract:

    In order to localize the epitopes of equine chorionic gonadotropin (eCG) involved in Interaction with luteinizing Hormone (LH) and follicle-stimulating Hormone (FSH) Receptors, we used 14 monoclonal anti-eCG antibodies (mAbs). Different effects of these mAbs on the bioactivities of eCG were observed in in vitro bioassays, but the effects of each mAb on the two bioactivities were similar for all but four mAbs. All mAbs were found to inhibit the binding of eCG to LH Receptors except 3A3 mAb, in radioReceptor assay. Six mAbs, which were strong inhibitors of eCG binding to LH Receptors and of both bioactivities, recognized the same area on the alpha subunit of eCG. All others, except 3A3, recognized epitopes close to the former, and close to each other. 3A3 mAb had a hyperstimulatory effect on FSH bioactivity, and was the only mAb that did not inhibit binding. It appeared to recognize a different epitopic area. These observations suggest that there is a main antigenic area on eCG, which corresponds to the Interaction site of eCG with both Receptors. It mostly involves the alpha subunit and to a lesser extent the beta subunit.

Yves Combarnous - One of the best experts on this subject based on the ideXlab platform.

  • topography of equine chorionic gonadotropin epitopes relative to the luteinizing Hormone and follicle stimulating Hormone Receptor Interaction sites
    Molecular and Cellular Endocrinology, 1993
    Co-Authors: M Chopineau, Yves Combarnous, Marie-christine Maurel, Philippe Durand
    Abstract:

    Abstract In order to localize the epitopes of equine chorionic gonadotropin (eCG) involved in Interaction with luteinizing Hormone (LH) and follicle-stimulating Hormone (FSH) Receptors, we used 14 monoclonal anti-eCG antibodies (mAbs). Different effects of these mAbs on the bioactivities of eCG were observed in in vitro bioassays, but the effects of each mAb on the two bioactivities were similar for all but four mAbs. All mAbs were found to inhibit the binding of eCG to LH Receptors except 3A3 mAb, in radioReceptor assay. Six mAbs, which were strong inhibitors of eCG binding to LH Receptors and of both bioactivities, recognized the same area on the α subunit of eCG. All others, except 3A3, recognized epitopes close to the former, and close to each other. 3A3 mAb had a hyperstimulatory effect on FSH bioactivity, and was the only mAb that did not inhibit binding. It appeared to recognize a different epitopic area. These observations suggest that there is a main antigenic area on eCG, which corresponds to the Interaction site of eCG with both Receptors. It mostly involves the α subunit and to a lesser extent the β subunit.

  • topography of equine chorionic gonadotropin epitopes relative to the luteinizing Hormone and follicle stimulating Hormone Receptor Interaction sites
    Molecular and Cellular Endocrinology, 1993
    Co-Authors: M Chopineau, Yves Combarnous, Marie-christine Maurel, Philippe Durand
    Abstract:

    In order to localize the epitopes of equine chorionic gonadotropin (eCG) involved in Interaction with luteinizing Hormone (LH) and follicle-stimulating Hormone (FSH) Receptors, we used 14 monoclonal anti-eCG antibodies (mAbs). Different effects of these mAbs on the bioactivities of eCG were observed in in vitro bioassays, but the effects of each mAb on the two bioactivities were similar for all but four mAbs. All mAbs were found to inhibit the binding of eCG to LH Receptors except 3A3 mAb, in radioReceptor assay. Six mAbs, which were strong inhibitors of eCG binding to LH Receptors and of both bioactivities, recognized the same area on the alpha subunit of eCG. All others, except 3A3, recognized epitopes close to the former, and close to each other. 3A3 mAb had a hyperstimulatory effect on FSH bioactivity, and was the only mAb that did not inhibit binding. It appeared to recognize a different epitopic area. These observations suggest that there is a main antigenic area on eCG, which corresponds to the Interaction site of eCG with both Receptors. It mostly involves the alpha subunit and to a lesser extent the beta subunit.

  • immunochemical study of equine chorionic gonadotropin ecg pmsg antigenic determinants on α and β subunits
    Biochimica et Biophysica Acta, 1992
    Co-Authors: Marie-christine Maurel, Jean Michel Bidart, Yves Combarnous
    Abstract:

    Abstract In the present study we have established an immunochemical mapping of equine Chorionic Gonadotropin (eCG/PMSG) using three monoclonal antibodies (mAbs), namely the antibodies ECG01, E10 and D7, raised against the native Hormone. These antibodies do not bind to reduced, alkylated Hormone, suggesting that they recognize discontinuous rather than continuous epitopes. We have also assessed the reactivity of mAbs towards human CG, and ovine, porcine, equine and bovine LH and FSH. The antigenic determinant recognized by ECG01 is localized on the α-subunit of equine gonadotropins and of human CG and LH. The epitopes recognized by E10 and D7 mAbs appear to be very similar and are present on the β-subunit of eCG and of LHs from all species tested, except hLH, as well as on porcine and equine FSHs. Attempts to specify the amino-acid residues involved in these epitopes suggest that ECG01 mAb might preferentially bind to residues around position 70 whereas the region around disulfide bridges Cys-88-Cys-90 might be involved in the epitopes recognized by D7 and E10 mAbs. Topographical relationships of epitopes show that ECG01 mAb never binds to eCG simultaneously with either D7 or E10 mAbs. Furthermore, simultaneous binding of D7 and E10 mAbs on eCG could not be achieved. Thus, these three epitopes appear to be closely located on the surface of eCG. Finally, ECG01 mAb inhibits eCG binding to LH and FSH Receptors, suggesting that its antigenic site is closely related to Hormone-Receptor Interaction site(s).

Marie-christine Maurel - One of the best experts on this subject based on the ideXlab platform.

  • topography of equine chorionic gonadotropin epitopes relative to the luteinizing Hormone and follicle stimulating Hormone Receptor Interaction sites
    Molecular and Cellular Endocrinology, 1993
    Co-Authors: M Chopineau, Yves Combarnous, Marie-christine Maurel, Philippe Durand
    Abstract:

    Abstract In order to localize the epitopes of equine chorionic gonadotropin (eCG) involved in Interaction with luteinizing Hormone (LH) and follicle-stimulating Hormone (FSH) Receptors, we used 14 monoclonal anti-eCG antibodies (mAbs). Different effects of these mAbs on the bioactivities of eCG were observed in in vitro bioassays, but the effects of each mAb on the two bioactivities were similar for all but four mAbs. All mAbs were found to inhibit the binding of eCG to LH Receptors except 3A3 mAb, in radioReceptor assay. Six mAbs, which were strong inhibitors of eCG binding to LH Receptors and of both bioactivities, recognized the same area on the α subunit of eCG. All others, except 3A3, recognized epitopes close to the former, and close to each other. 3A3 mAb had a hyperstimulatory effect on FSH bioactivity, and was the only mAb that did not inhibit binding. It appeared to recognize a different epitopic area. These observations suggest that there is a main antigenic area on eCG, which corresponds to the Interaction site of eCG with both Receptors. It mostly involves the α subunit and to a lesser extent the β subunit.

  • topography of equine chorionic gonadotropin epitopes relative to the luteinizing Hormone and follicle stimulating Hormone Receptor Interaction sites
    Molecular and Cellular Endocrinology, 1993
    Co-Authors: M Chopineau, Yves Combarnous, Marie-christine Maurel, Philippe Durand
    Abstract:

    In order to localize the epitopes of equine chorionic gonadotropin (eCG) involved in Interaction with luteinizing Hormone (LH) and follicle-stimulating Hormone (FSH) Receptors, we used 14 monoclonal anti-eCG antibodies (mAbs). Different effects of these mAbs on the bioactivities of eCG were observed in in vitro bioassays, but the effects of each mAb on the two bioactivities were similar for all but four mAbs. All mAbs were found to inhibit the binding of eCG to LH Receptors except 3A3 mAb, in radioReceptor assay. Six mAbs, which were strong inhibitors of eCG binding to LH Receptors and of both bioactivities, recognized the same area on the alpha subunit of eCG. All others, except 3A3, recognized epitopes close to the former, and close to each other. 3A3 mAb had a hyperstimulatory effect on FSH bioactivity, and was the only mAb that did not inhibit binding. It appeared to recognize a different epitopic area. These observations suggest that there is a main antigenic area on eCG, which corresponds to the Interaction site of eCG with both Receptors. It mostly involves the alpha subunit and to a lesser extent the beta subunit.

  • immunochemical study of equine chorionic gonadotropin ecg pmsg antigenic determinants on α and β subunits
    Biochimica et Biophysica Acta, 1992
    Co-Authors: Marie-christine Maurel, Jean Michel Bidart, Yves Combarnous
    Abstract:

    Abstract In the present study we have established an immunochemical mapping of equine Chorionic Gonadotropin (eCG/PMSG) using three monoclonal antibodies (mAbs), namely the antibodies ECG01, E10 and D7, raised against the native Hormone. These antibodies do not bind to reduced, alkylated Hormone, suggesting that they recognize discontinuous rather than continuous epitopes. We have also assessed the reactivity of mAbs towards human CG, and ovine, porcine, equine and bovine LH and FSH. The antigenic determinant recognized by ECG01 is localized on the α-subunit of equine gonadotropins and of human CG and LH. The epitopes recognized by E10 and D7 mAbs appear to be very similar and are present on the β-subunit of eCG and of LHs from all species tested, except hLH, as well as on porcine and equine FSHs. Attempts to specify the amino-acid residues involved in these epitopes suggest that ECG01 mAb might preferentially bind to residues around position 70 whereas the region around disulfide bridges Cys-88-Cys-90 might be involved in the epitopes recognized by D7 and E10 mAbs. Topographical relationships of epitopes show that ECG01 mAb never binds to eCG simultaneously with either D7 or E10 mAbs. Furthermore, simultaneous binding of D7 and E10 mAbs on eCG could not be achieved. Thus, these three epitopes appear to be closely located on the surface of eCG. Finally, ECG01 mAb inhibits eCG binding to LH and FSH Receptors, suggesting that its antigenic site is closely related to Hormone-Receptor Interaction site(s).

Gerd Krause - One of the best experts on this subject based on the ideXlab platform.

  • Differences in Signal Activation by LH and hCG are Mediated by the LH/CG Receptor’s Extracellular Hinge Region
    Frontiers in Endocrinology, 2015
    Co-Authors: Paul Grzesik, Annika Kreuchwig, Claudia Rutz, Jens Furkert, Burkhard Wiesner, Ralf Schuelein, Gunnar Kleinau, Joerg Gromoll, Gerd Krause
    Abstract:

    The human lutropin/choriogonadotropin Receptor (LHCGR) can be activated by binding two slightly different gonadotropic glycoprotein Hormones, choriogonadotropin (CG) - secreted by the placenta, and lutropin (LH) - produced by the pituitary. They induce different signaling profiles at the LHCGR. This cannot be explained by binding to the Receptor's leucine-rich repeat domain (LRRD), as this binding is similar for the two Hormones. We therefore speculate that there are previously unknown differences in the Hormone/Receptor Interaction at the extracellular hinge region, which might help to understand functional differences between the two Hormones. We have therefore performed a detailed study of the binding and action of LH and CG at the LHCGR hinge region. We focused on a primate-specific additional exon in the hinge region, which is located between LRRD and the serpentine domain. The segment of the hinge region encoded by exon10 was previously reported to be only relevant to hLH signaling, as the exon10-deletion Receptor exhibits decreased hLH signaling, but unchanged hCG signaling. We designed an advanced homology model of the Hormone/LHCGR complex, followed by experimental characterization of relevant fragments in the hinge region. In addition, we examined predictions of a helical exon10-encoded conformation by block-wise polyalanine (helix supporting) mutations. These helix preserving modifications showed no effect on Hormone induced signaling. However, introduction of a structure-disturbing double-proline mutant LHCGR-Q303P/E305P within the exon10-helix has, in contrast to exon10 deletion, no impact on hLH, but only on hCG signaling. This opposite effect on signaling by hLH and hCG can be explained by distinct sites of Hormone Interaction in the hinge region s. In conclusion, our analysis provides details of the differences between hLH- and hCG-induced signaling that are mainly determined in the L2-beta loop of the Hormones and in the hinge region of the Receptor

  • differences in signal activation by lh and hcg are mediated by the lh cg Receptor s extracellular hinge region
    Frontiers in Endocrinology, 2015
    Co-Authors: Paul Grzesik, Annika Kreuchwig, Claudia Rutz, Jens Furkert, Burkhard Wiesner, Ralf Schuelein, Gunnar Kleinau, Joerg Gromoll, Gerd Krause
    Abstract:

    The human lutropin/choriogonadotropin Receptor (LHCGR) can be activated by binding two slightly different gonadotropic glycoprotein Hormones, choriogonadotropin (CG) - secreted by the placenta, and lutropin (LH) - produced by the pituitary. They induce different signaling profiles at the LHCGR. This cannot be explained by binding to the Receptor's leucine-rich repeat domain (LRRD), as this binding is similar for the two Hormones. We therefore speculate that there are previously unknown differences in the Hormone/Receptor Interaction at the extracellular hinge region, which might help to understand functional differences between the two Hormones. We have therefore performed a detailed study of the binding and action of LH and CG at the LHCGR hinge region. We focused on a primate-specific additional exon in the hinge region, which is located between LRRD and the serpentine domain. The segment of the hinge region encoded by exon10 was previously reported to be only relevant to hLH signaling, as the exon10-deletion Receptor exhibits decreased hLH signaling, but unchanged hCG signaling. We designed an advanced homology model of the Hormone/LHCGR complex, followed by experimental characterization of relevant fragments in the hinge region. In addition, we examined predictions of a helical exon10-encoded conformation by block-wise polyalanine (helix supporting) mutations. These helix preserving modifications showed no effect on Hormone induced signaling. However, introduction of a structure-disturbing double-proline mutant LHCGR-Q303P/E305P within the exon10-helix has, in contrast to exon10 deletion, no impact on hLH, but only on hCG signaling. This opposite effect on signaling by hLH and hCG can be explained by distinct sites of Hormone Interaction in the hinge region s. In conclusion, our analysis provides details of the differences between hLH- and hCG-induced signaling that are mainly determined in the L2-beta loop of the Hormones and in the hinge region of the Receptor

M Chopineau - One of the best experts on this subject based on the ideXlab platform.

  • topography of equine chorionic gonadotropin epitopes relative to the luteinizing Hormone and follicle stimulating Hormone Receptor Interaction sites
    Molecular and Cellular Endocrinology, 1993
    Co-Authors: M Chopineau, Yves Combarnous, Marie-christine Maurel, Philippe Durand
    Abstract:

    Abstract In order to localize the epitopes of equine chorionic gonadotropin (eCG) involved in Interaction with luteinizing Hormone (LH) and follicle-stimulating Hormone (FSH) Receptors, we used 14 monoclonal anti-eCG antibodies (mAbs). Different effects of these mAbs on the bioactivities of eCG were observed in in vitro bioassays, but the effects of each mAb on the two bioactivities were similar for all but four mAbs. All mAbs were found to inhibit the binding of eCG to LH Receptors except 3A3 mAb, in radioReceptor assay. Six mAbs, which were strong inhibitors of eCG binding to LH Receptors and of both bioactivities, recognized the same area on the α subunit of eCG. All others, except 3A3, recognized epitopes close to the former, and close to each other. 3A3 mAb had a hyperstimulatory effect on FSH bioactivity, and was the only mAb that did not inhibit binding. It appeared to recognize a different epitopic area. These observations suggest that there is a main antigenic area on eCG, which corresponds to the Interaction site of eCG with both Receptors. It mostly involves the α subunit and to a lesser extent the β subunit.

  • topography of equine chorionic gonadotropin epitopes relative to the luteinizing Hormone and follicle stimulating Hormone Receptor Interaction sites
    Molecular and Cellular Endocrinology, 1993
    Co-Authors: M Chopineau, Yves Combarnous, Marie-christine Maurel, Philippe Durand
    Abstract:

    In order to localize the epitopes of equine chorionic gonadotropin (eCG) involved in Interaction with luteinizing Hormone (LH) and follicle-stimulating Hormone (FSH) Receptors, we used 14 monoclonal anti-eCG antibodies (mAbs). Different effects of these mAbs on the bioactivities of eCG were observed in in vitro bioassays, but the effects of each mAb on the two bioactivities were similar for all but four mAbs. All mAbs were found to inhibit the binding of eCG to LH Receptors except 3A3 mAb, in radioReceptor assay. Six mAbs, which were strong inhibitors of eCG binding to LH Receptors and of both bioactivities, recognized the same area on the alpha subunit of eCG. All others, except 3A3, recognized epitopes close to the former, and close to each other. 3A3 mAb had a hyperstimulatory effect on FSH bioactivity, and was the only mAb that did not inhibit binding. It appeared to recognize a different epitopic area. These observations suggest that there is a main antigenic area on eCG, which corresponds to the Interaction site of eCG with both Receptors. It mostly involves the alpha subunit and to a lesser extent the beta subunit.