Abstract
An immunoadsorption technique employing a rabbit antiserum specific for human serum prealbumin has been devised to remove thyroxine (T4)-binding prealbumin (TBPA) from serum completely without affecting the T4-binding activity of thyroxine-binding globulin (TBG) or the concentration of the other major proteins in serum. As judged from the proportion of T4 associated with the antigen-antibody precipitate, only about 15% of the endogenous T4 is bound by TBPA, a value considerably less than that indicated by electrophoretic methods. As judged from the increase in the proportion of free T4 that followed immunoadsorption of TBPA, TBPA does act as one determinant of the proportion of free T4 but is far less important than TBG in this respect. A decrease in the T4-binding capacity of TBPA cannot solely account for the increase in the proportion of free T4 in the sera of ill patients, since a comparable increase does not occur in normal sera after complete removal of TBPA. From data obtained in normal and abnormal sera before and after immunoadsorption of TBPA, estimates of the equilibrium constants for the interactions between T4 and its binding proteins, as they exist in serum, have been derived. The values obtained were: KALB, 6.2 × 105; KTBPA, 2.3 × 108; and KTBG, 1.7 × 1010.
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- BLUMBERG B. S., ROBBINS J. Thyroxine-serum protein complexes: single dimension gel and paper electrophoresis studies. Endocrinology. 1960 Sep;67:368–378. doi: 10.1210/endo-67-3-368. [DOI] [PubMed] [Google Scholar]
- ELZINGA K. E., CARR E. A., Jr, BEIERWALTES W. H. Adaptation of the standard Durrum-type cell for reverse-flow paper electrophoresis. Am J Clin Pathol. 1961 Aug;36:125–131. doi: 10.1093/ajcp/36.2.125. [DOI] [PubMed] [Google Scholar]
- FAHEY J. L., McCOY P. F., GOULIAN M. Chromatography of serum proteins in normal and pathologic sera: the distribution of protein-bound carbohydrate and cholesterol, siderophilin, thyroxin-binding protein, B12-binding protein, alkaline and acid phosphatases, radio-iodinated albumin and myeloma proteins. J Clin Invest. 1958 Feb;37(2):272–284. doi: 10.1172/JCI103606. [DOI] [PMC free article] [PubMed] [Google Scholar]
- HOLLANDER C. S., ODAK V. V., PROUT T. E., ASPER S. P., Jr An evaluation of the role of prealbumin in the binding of thyroxine. J Clin Endocrinol Metab. 1962 Jun;22:617–622. doi: 10.1210/jcem-22-6-617. [DOI] [PubMed] [Google Scholar]
- INGBAR S. H., FREINKEL N. Regulation of the peripheral metabolism of the thyroid hormones. Recent Prog Horm Res. 1960;16:353–403. [PubMed] [Google Scholar]
- INGBAR S. H. Observations concerning the binding of thyroid hormones by human serum prealbumin. J Clin Invest. 1963 Feb;42:143–160. doi: 10.1172/JCI104701. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Inada M., Sterling K. Thyroxine transport in thyrotoxicosis and hypothyroidism. J Clin Invest. 1967 Sep;46(9):1442–1450. doi: 10.1172/JCI105636. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Ingbar S. H., Braverman L. E., Dawber N. A., Lee G. Y. A new method for measuring the free thyroid hormone in human serum and an analysis of the factors that influence its concentration. J Clin Invest. 1965 Oct;44(10):1679–1689. doi: 10.1172/JCI105275. [DOI] [PMC free article] [PubMed] [Google Scholar]
- MURPHY B. E., PATTEE C. J. DETERMINATION OF THYROXINE UTILIZING THE PROPERTY OF PROTEIN-BINDING. J Clin Endocrinol Metab. 1964 Feb;24:187–196. doi: 10.1210/jcem-24-2-187. [DOI] [PubMed] [Google Scholar]
- OPPENHEIMER J. H., SQUEF R., SURKS M. I., HAUER H. BINDING OF THYROXINE BY SERUM PROTEINS EVALUATED BY EQUILIBRUM DIALYSIS AND ELECTROPHORETIC TECHNIQUES. ALTERATIONS IN NONTHYROIDAL ILLNESS. J Clin Invest. 1963 Nov;42:1769–1782. doi: 10.1172/JCI104862. [DOI] [PMC free article] [PubMed] [Google Scholar]
- OPPENHEIMER J. H., SURKS M. I. DETERMINATION OF FREE THYROXINE IN HUMAN SERUM: A THEORETICAL AND EXPERIMENTAL ANALYSIS. J Clin Endocrinol Metab. 1964 Aug;24:785–793. doi: 10.1210/jcem-24-8-785. [DOI] [PubMed] [Google Scholar]
- OPPENHEIMER J. H., SURKS M. I., SMITH J. C., SQUEF R. ISOLATION AND CHARACTERIZATION OF HUMAN THYROXINE-BINDING PREALBUMIN. J Biol Chem. 1965 Jan;240:173–180. [PubMed] [Google Scholar]
- RICH C., BEARN A. G. Localization of the thyroxine-binding protein of serum by starch gel electrophoresis. Endocrinology. 1958 May;62(5):687–689. doi: 10.1210/endo-62-5-687. [DOI] [PubMed] [Google Scholar]
- ROBBINS J., RALL J. E. Proteins associated with the thyroid hormones. Physiol Rev. 1960 Jul;40:415–489. doi: 10.1152/physrev.1960.40.3.415. [DOI] [PubMed] [Google Scholar]
- SQUEF R., MARTINEZ M., OPPENHEIMER J. H. USE OF THYROXINE-DISPLACING DRUGS IN IDENTIFYING SERUM THYROXINE-BINDING PROTEINS SEPARATED BY STARCH GEL ELECTROPHORESIS. Proc Soc Exp Biol Med. 1963 Aug-Sep;113:837–840. doi: 10.3181/00379727-113-28506. [DOI] [PubMed] [Google Scholar]
- Schussler G. C., Plager J. E. Effect of preliminary purification of 131-I-thyroxine on the determination of free thyroxine in serum. J Clin Endocrinol Metab. 1967 Feb;27(2):242–250. doi: 10.1210/jcem-27-2-242. [DOI] [PubMed] [Google Scholar]
- Steiner R. F., Roth J., Robbins J. The binding of thyroxine by serum albumin as measured by fluorescence quenching. J Biol Chem. 1966 Feb 10;241(3):560–567. [PubMed] [Google Scholar]
- Sterling K., Brenner M. A. Free thyroxine in human serum: simplified measurement with the aid of magnesium precipitation. J Clin Invest. 1966 Jan;45(1):153–163. doi: 10.1172/JCI105320. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Tabachnick M. Thyroxine-protein interactions. IV. Thermodynamic values for the association of thyroxine with human serum albumin. J Biol Chem. 1967 Apr 10;242(7):1646–1650. [PubMed] [Google Scholar]