{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,5]],"date-time":"2026-03-05T23:26:01Z","timestamp":1772753161108,"version":"3.50.1"},"reference-count":0,"publisher":"Portland Press Ltd.","issue":"3","content-domain":{"domain":["portlandpress.com"],"crossmark-restriction":true},"short-container-title":[],"published-print":{"date-parts":[[1977,12,1]]},"abstract":"<jats:p>Protein-A-Fc-fragment complexes were observed in sedimentation-velocity experiments by ultracentrifugation. The interaction was studied by protein-fluorescence-quenching titrations of the Fc fragment with protein A, allowing the dissociation constant to be determined under a variety of conditions. The first component of the complement pathway, C1, is activated by complexes of protein A with rabbit IgG (immunoglobulin G), and the structural basis for this interaction was studied by using n.m.r. (nuclear magnetic resonance). The four Fc-fragment binding sites on protein A were shown to contain aromatic amino acids, and to be connected by mobile hydrophilic regions. Neither n.m.r. nor proton-relaxation-enhancement studies show evidence of a large conformational change of the Fc fragment on binding protein A, and this suggests that the cross-linking of the Fc fragments may be primarily responsible for the activation of component C1. This is supported by the inability of a univalent tryptic fragment of protein A to activate complement fixation by rabbit IgG.<\/jats:p>","DOI":"10.1042\/bj1670661","type":"journal-article","created":{"date-parts":[[2015,8,13]],"date-time":"2015-08-13T21:38:42Z","timestamp":1439501922000},"page":"661-668","update-policy":"https:\/\/doi.org\/10.1042\/crossmark_policy","source":"Crossref","is-referenced-by-count":31,"title":["The interaction of protein A and Fc fragment of rabbit immunoglobulin G as probed by complement-fixation and nuclear-magnetic-resonance studies"],"prefix":"10.1042","volume":"167","author":[{"given":"C","family":"Wright","sequence":"first","affiliation":[]},{"given":"K J","family":"Willan","sequence":"additional","affiliation":[]},{"given":"J","family":"Sj\u00f6dahl","sequence":"additional","affiliation":[]},{"given":"D R","family":"Burton","sequence":"additional","affiliation":[]},{"given":"R A","family":"Dwek","sequence":"additional","affiliation":[]}],"member":"288","container-title":["Biochemical Journal"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/portlandpress.com\/biochemj\/article-pdf\/167\/3\/661\/616552\/bj1670661.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/portlandpress.com\/biochemj\/article-pdf\/167\/3\/661\/616552\/bj1670661.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2021,11,26]],"date-time":"2021-11-26T18:10:05Z","timestamp":1637950205000},"score":1,"resource":{"primary":{"URL":"https:\/\/portlandpress.com\/biochemj\/article\/167\/3\/661\/12285\/The-interaction-of-protein-A-and-Fc-fragment-of"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1977,12,1]]},"references-count":0,"journal-issue":{"issue":"3","published-print":{"date-parts":[[1977,12,1]]}},"URL":"https:\/\/doi.org\/10.1042\/bj1670661","relation":{},"ISSN":["0264-6021"],"issn-type":[{"value":"0264-6021","type":"print"}],"subject":[],"published":{"date-parts":[[1977,12,1]]}}}