In vitro formation of apparent covalent complexes between L-triiodothyronine and plasma protein

Diona Koerner, Martin I. Surks, Jack H. Oppenheimer

Research output: Contribution to journalArticle

7 Scopus citations


Nondissociable complexes between125I-labeled T3 (125I-T3) and plasma proteins were observed after incubation of125I-T3 with plasma diluted 200-fold with phosphate buffer. The formation of these complexes was enhanced in the presence of Cu2+ and flavin mononucleotide and inhibited by reducing agents such as propylthiouracil, thiosulfate, dithiothreitol, and glutathione. The125I-T3 protein complexes could be disrupted after digestion with pronase. T3 itself was identified as a constituent of the pronase digests by co-chromatography with authentic131I-T3 to a constant isotopic ratio across the T3 area. Since treatment with 0.2% sodium dodecylsulfate or 8M urea did not disrupt the complexes, the T3-protein bond appears to have some of the characteristics of a covalent bond between hormone and protein.

Original languageEnglish (US)
Pages (from-to)239-245
Number of pages7
JournalJournal of Clinical Endocrinology and Metabolism
Issue number2
Publication statusPublished - Feb 1973


ASJC Scopus subject areas

  • Endocrinology, Diabetes and Metabolism
  • Biochemistry
  • Endocrinology
  • Clinical Biochemistry
  • Biochemistry, medical

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