{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T13:30:46Z","timestamp":1760189446791},"reference-count":0,"publisher":"Portland Press Ltd.","issue":"1","content-domain":{"domain":["portlandpress.com"],"crossmark-restriction":true},"short-container-title":[],"published-print":{"date-parts":[[1988,5,15]]},"abstract":"<jats:p>Bombesin and bombesin-related peptides such as gastrin-releasing peptide (GRP) stimulate DNA synthesis and proliferation of Swiss 3T3 cells in culture. We have used 125I-labelled [Tyr4]bombesin and 125I-labelled GRP to characterize and identify the receptors for these peptides on Swiss 3T3 cells. The binding of 125I-[Tyr4]bombesin, which retained full biological activity, was maximal between 20 and 30 min incubation at 37 degrees C, after which continued incubation led to a decline in cell-associated radioactivity. This decline was markedly slowed by the presence of lysosomal enzyme inhibitors. Specificity of the binding site was indicated by the competitive inhibition of binding by bombesin-related peptides, but not by unrelated peptides and growth factors. Scatchard analysis of binding data indicated a single class of high-affinity receptors. The calculated value for the dissociation constant (Kd) was 2.1 nM and each cell possesses approx. 240,000 receptors. Because [Tyr4]bombesin has no free amino group, 125I-GRP was used in chemical cross-linking studies. When disuccinimidyl suberate was used to covalently couple 125I-GRP to the cells, two major radiolabelled complexes were detected with molecular masses of approx. 80,000-85,000 and 140,000. The binding of 125I-[Tyr4]bombesin to the cells was pH-dependent with maximal binding at pH 6.5-7.5 and effectively no specific binding at pH values below 4.5. At 37 degrees C, cell-associated 125I-[Tyr4]bombesin quickly became resistant to removal by acidic buffers, suggesting its rapid transfer to an intracellular compartment. However, pre-incubation with unlabelled [Tyr4]bombesin did not induce down-regulation of bombesin receptors as measured by the subsequent binding of 125I-[Tyr4]bombesin. In contrast with the Swiss 3T3 cells, specific binding of 125I-[Tyr4]bombesin was not detectable in two cell lines which are biologically unresponsive to bombesin-related peptides.<\/jats:p>","DOI":"10.1042\/bj2520227","type":"journal-article","created":{"date-parts":[[2015,8,10]],"date-time":"2015-08-10T21:11:17Z","timestamp":1439241077000},"page":"227-235","update-policy":"http:\/\/dx.doi.org\/10.1042\/crossmark_policy","source":"Crossref","is-referenced-by-count":21,"title":["Characterization of the high-affinity receptors on Swiss 3T3 cells which mediate the binding, internalization and degradation of the mitogenic peptide bombesin"],"prefix":"10.1042","volume":"252","author":[{"given":"K D","family":"Brown","sequence":"first","affiliation":[{"name":"AFRC Institute of Animal Physiology, Babraham, Cambridge, U.K."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"M S","family":"Laurie","sequence":"additional","affiliation":[{"name":"AFRC Institute of Animal Physiology, Babraham, Cambridge, U.K."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"C J","family":"Littlewood","sequence":"additional","affiliation":[{"name":"AFRC Institute of Animal Physiology, Babraham, Cambridge, U.K."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"D M","family":"Blakeley","sequence":"additional","affiliation":[{"name":"AFRC Institute of Animal Physiology, Babraham, Cambridge, U.K."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"A N","family":"Corps","sequence":"additional","affiliation":[{"name":"AFRC Institute of Animal Physiology, Babraham, Cambridge, U.K."}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"288","container-title":["Biochemical Journal"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/portlandpress.com\/biochemj\/article-pdf\/252\/1\/227\/593270\/bj2520227.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/portlandpress.com\/biochemj\/article-pdf\/252\/1\/227\/593270\/bj2520227.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2021,11,25]],"date-time":"2021-11-25T19:31:14Z","timestamp":1637868674000},"score":1,"resource":{"primary":{"URL":"https:\/\/portlandpress.com\/biochemj\/article\/252\/1\/227\/95704\/Characterization-of-the-high-affinity-receptors-on"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1988,5,15]]},"references-count":0,"journal-issue":{"issue":"1","published-print":{"date-parts":[[1988,5,15]]}},"URL":"https:\/\/doi.org\/10.1042\/bj2520227","relation":{},"ISSN":["0264-6021","1470-8728"],"issn-type":[{"value":"0264-6021","type":"print"},{"value":"1470-8728","type":"electronic"}],"subject":[],"published":{"date-parts":[[1988,5,15]]}}}