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Variant thyroxine-binding globulin in serum of Australian aborigines: its physical, chemical and biological properties.
J Endocrinol Invest. 1985 Jun; 8(3):225-32.JE

Abstract

Low serum total thyroxine (TT4) and triiodothyronine (TT3) is found in approximately 40% of Australian Aborigines. Studies were carried out to characterize the properties of thyroxine-binding globulin (TBG) in these Australian Aborigines to explain the observed reduction of thyroid hormone concentration in their serum. TBG from Aborigines with low serum TT4 concentrations was compared to TBG from Aborigines with normal TT4 concentration and Caucasians and American Blacks with normal or reduced serum TBG levels due to familial partial TBG deficiency. TBG from Aborigines with low serum TT4 concentrations had a reduced affinity for thyroid hormone (Ka). The Ka for T4 was 54% and for T3 30% of the Ka values for TBG from Aborigines with normal TT4 concentration or non-Aborigines. Maximal binding values were in agreement with TBG measurements by RIA for Aborigines with low or normal serum TT4 and for non-Aborigines. An increase in the rate of heat denaturation of TBG at temperatures from 54 to 60 C was also observed in sera from Aborigines with low TT4. The heat lability was lowered by 2 C. The low concentration of TT4 in serum of these Aborigines could not explain this higher heat lability of TBG since only addition of greater than 80-fold the physiologic T4 concentration obliterated the difference of heat inactivation by denaturation.(

ABSTRACT

TRUNCATED AT 250 WORDS)

Authors

No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, U.S. Gov't, P.H.S.

Language

eng

PubMed ID

3928734

Citation

Murata, Y, et al. "Variant Thyroxine-binding Globulin in Serum of Australian Aborigines: Its Physical, Chemical and Biological Properties." Journal of Endocrinological Investigation, vol. 8, no. 3, 1985, pp. 225-32.
Murata Y, Refetoff S, Sarne DH, et al. Variant thyroxine-binding globulin in serum of Australian aborigines: its physical, chemical and biological properties. J Endocrinol Invest. 1985;8(3):225-32.
Murata, Y., Refetoff, S., Sarne, D. H., Dick, M., & Watson, F. (1985). Variant thyroxine-binding globulin in serum of Australian aborigines: its physical, chemical and biological properties. Journal of Endocrinological Investigation, 8(3), 225-32.
Murata Y, et al. Variant Thyroxine-binding Globulin in Serum of Australian Aborigines: Its Physical, Chemical and Biological Properties. J Endocrinol Invest. 1985;8(3):225-32. PubMed PMID: 3928734.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Variant thyroxine-binding globulin in serum of Australian aborigines: its physical, chemical and biological properties. AU - Murata,Y, AU - Refetoff,S, AU - Sarne,D H, AU - Dick,M, AU - Watson,F, PY - 1985/6/1/pubmed PY - 1985/6/1/medline PY - 1985/6/1/entrez SP - 225 EP - 32 JF - Journal of endocrinological investigation JO - J. Endocrinol. Invest. VL - 8 IS - 3 N2 - Low serum total thyroxine (TT4) and triiodothyronine (TT3) is found in approximately 40% of Australian Aborigines. Studies were carried out to characterize the properties of thyroxine-binding globulin (TBG) in these Australian Aborigines to explain the observed reduction of thyroid hormone concentration in their serum. TBG from Aborigines with low serum TT4 concentrations was compared to TBG from Aborigines with normal TT4 concentration and Caucasians and American Blacks with normal or reduced serum TBG levels due to familial partial TBG deficiency. TBG from Aborigines with low serum TT4 concentrations had a reduced affinity for thyroid hormone (Ka). The Ka for T4 was 54% and for T3 30% of the Ka values for TBG from Aborigines with normal TT4 concentration or non-Aborigines. Maximal binding values were in agreement with TBG measurements by RIA for Aborigines with low or normal serum TT4 and for non-Aborigines. An increase in the rate of heat denaturation of TBG at temperatures from 54 to 60 C was also observed in sera from Aborigines with low TT4. The heat lability was lowered by 2 C. The low concentration of TT4 in serum of these Aborigines could not explain this higher heat lability of TBG since only addition of greater than 80-fold the physiologic T4 concentration obliterated the difference of heat inactivation by denaturation.(ABSTRACT TRUNCATED AT 250 WORDS) SN - 0391-4097 UR - https://www.unboundmedicine.com/medline/citation/3928734/Variant_thyroxine_binding_globulin_in_serum_of_Australian_aborigines:_its_physical_chemical_and_biological_properties_ L2 - https://link.springer.com/article/10.1007/BF03348482 DB - PRIME DP - Unbound Medicine ER -