{"id":1174,"date":"2019-06-17T19:35:54","date_gmt":"2019-06-17T11:35:54","guid":{"rendered":"http:\/\/www.bioactivescreeninglibrary.com\/?p=1174"},"modified":"2022-01-07T10:53:32","modified_gmt":"2022-01-07T02:53:32","slug":"molecular-details-receptor-activation-limitation-include-receptor-misfolding-constraining-receptor-conformational","status":"publish","type":"post","link":"http:\/\/www.bioactivescreeninglibrary.com\/index.php\/2019\/06\/17\/molecular-details-receptor-activation-limitation-include-receptor-misfolding-constraining-receptor-conformational\/","title":{"rendered":"The molecular details of receptor activation limitation include receptor misfolding and constraining of the receptor into conformational"},"content":{"rendered":"

In contrast, antibodies, both polyclonal and monoclonal, have exquisite conformational specificity and extensively used in hormone-receptor interactions studies. Our earlier studies using agonistic FSHR hinge antibody as well as Cinoxacin<\/a> Extensive use of polyclonal and monoclonal antibodies in investigation of structure-function relationship of TSHR and its ligands clearly indicate the expediency of using such antibodies in studying the role of hinge region in receptor activation. In the present study, we have combined mutagenesis and novel TSHR MAbs to dissect out roles of different regions of the receptor in binding and signaling. Effect of MAbs on hTSH-TSHR interactions was further investigated by determining binding constants in presence of MAbs. Typical TSH radioreceptor assays were carried out after pre-incubating the receptor preparation with MAbs or NMIgG and the binding data was converted to the Scatchard plots and the binding constants calculated according to the legends of Figure 3. The Scatchard analysis of TSH-TSHR binding is typically curvilinear and for visual representation, only the physiologically relevant high affinity receptor component has been considered. The effect of the antibodies on the low affinity, high capacity components is, however, presented in Figure S10. As shown in Figure 3 and Table 1, MAbs 311.82 and 311.174 did not affect the TSH-receptor interactions, although a marginal decrease in the Bmax was observed in case of the latter MAb. The MAb 311.87 exhibited non-competitive inhibition with a significant decrease in Bmax and no change in the affinity. Extensive mutational analysis of the hinge region residues has shown the importance of the hinge region in hormone binding and receptor stimulation. These mutations, while providing valuable insights into receptor functioning, suffer from the stabilization of a Hammond state in the structural segment containing the mutation. By increasing or decreasing the energy barrier of activation, the mutation could allosterically stabilize a receptor conformation unsuitable for hormone binding, which may be misconstrued to be a part of the hormone-binding site. 3,4,5-Trimethoxyphenylacetic acid<\/a> Moreover, substitution of residues at the hinge region and LRR domain junction by charged residues cause misfolding of TSHR causing impairment of cell surface expression. MAbs on the other hand have the unique capability of differentiating between an allosteric and an orthosteric receptor site and have proved to be reliable tools in detecting the ligand induced conformational changes in the wild type or mutated receptors. TSHR stimulatory monoclonal antibodies have been instrumental in understanding TSH interaction with the LRR domain of TSHR or the N terminal region of ECD in receptor activation. Almost all the reported TSH stimulatory MAbs had epitopes in the LRR domain except TSAB-4 that recognized in the TSHR hinge region or all were full agonists except IRI-SAb1 and affected TSH binding. In contrast, MAb 311.62 is a hinge region specific partial agonistic MAb that does not inhibit TSH binding but stimulates the receptor. In the present study, MAB 311.62 and the antagonistic MAB 311.87 have been used to understand the mechanisms of hormone binding and receptor activation. It is expected that transmission of signal from the LRR to the TMD would require considerable conformational change in the receptor. It is highly unlikely that contact of the hormone at LRR 4\ufffdC6 alone can initiate such a conformational change owing to its rigid structure.<\/p>\n","protected":false},"excerpt":{"rendered":"

In contrast, antibodies, both polyclonal and monoclonal, have exquisite conformational specificity and extensively used in hormone-receptor interactions studies. Our earlier studies using agonistic FSHR hinge antibody as well as Cinoxacin Extensive use of polyclonal and monoclonal antibodies in investigation of structure-function relationship of TSHR and its ligands clearly indicate the expediency of using such antibodies … Continue reading “The molecular details of receptor activation limitation include receptor misfolding and constraining of the receptor into conformational”<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[1],"tags":[],"_links":{"self":[{"href":"http:\/\/www.bioactivescreeninglibrary.com\/index.php\/wp-json\/wp\/v2\/posts\/1174"}],"collection":[{"href":"http:\/\/www.bioactivescreeninglibrary.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.bioactivescreeninglibrary.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.bioactivescreeninglibrary.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/www.bioactivescreeninglibrary.com\/index.php\/wp-json\/wp\/v2\/comments?post=1174"}],"version-history":[{"count":1,"href":"http:\/\/www.bioactivescreeninglibrary.com\/index.php\/wp-json\/wp\/v2\/posts\/1174\/revisions"}],"predecessor-version":[{"id":1175,"href":"http:\/\/www.bioactivescreeninglibrary.com\/index.php\/wp-json\/wp\/v2\/posts\/1174\/revisions\/1175"}],"wp:attachment":[{"href":"http:\/\/www.bioactivescreeninglibrary.com\/index.php\/wp-json\/wp\/v2\/media?parent=1174"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.bioactivescreeninglibrary.com\/index.php\/wp-json\/wp\/v2\/categories?post=1174"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.bioactivescreeninglibrary.com\/index.php\/wp-json\/wp\/v2\/tags?post=1174"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}