Specific binding sites for 3,3′‐diiodo‐l‐thyronine (3,3′‐T2) in rat liver mitochondria

FEBS Letters

Lanni, Antonia¹  Fernando, Goglia¹  Lombardi, Assunta¹  Horst, Claus²  Moreno, Maria¹ 

[1] Dipartimento di Fisiologia Generale ed Ambientale, Università di Napoli, I-80134 Napoli, Italy;Marion Merrell Dow Research Institute, Henning Berlin R&D, D-12067 Berlin, Germany

关键词: Diiodothyronine;    Thyroid hormone;    Mitochondrai;    Receptor;    Cytochrome c oxidase;    T4;    thyroxine;    T3;    3;    3′;    5-triiodo-l-thyronine;    rT3 or revers T3;    3;    3′;    5′-triiodo-l-thyronine;    3;    3′-T2;    3;    3′-diiodo-l-thyronine;    3;    5-T2;    3;    5-diiodo-l-thyronine;    3′;    5′-T2;    3′5′-diiodo-l-thyronine;    3-T1;    3-monoiodo-l-thyronine;    3′-T1;    3′-monoiodo-l- thyronine;    3;    5-Diac;    3;    5-diiodothyroacetic acid;    3;    3′-Diac;    3;    3′-diiodothyroacetic acid;   

DOI  :  10.1016/0014-5793(94)00840-X

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Specific binding sites for 3,3′-T₂ can be detected in swollen and osmotically treated mitochondria (OTM) from normal and hypothyroid rat liver. In hypothyroid animals, maximal values of binding were obtained at 0°C and 20°C while values were lower at 37°C and no specific binding could be observed at 60°C. Binding was maximal at pH 6.4 and the mean values for the apparent association constant (K _a) and the binding capacity were on average 0.5 × 10⁸ M⁻¹ and 2.4 pmol/mg mitochondrial protein, respectively. No differences were observed between normal and hypothyroid rats with the exception of the capacity that was higher in normal animals (5.5 pmol/mg mitochondrial protein). The specificity of 3,3′-T₂ binding, examined in competition studies, followed this order: 3,3′-T₂ > 3,5-T₂ > rT₃. The other iodothyronines (3′,5′-T₂, T₃, T₄, 3-T₁, 3′-T₁, 3,5-Diac and 3,3′-Diac) showed only a small competition or none at all.

【 授权许可】

Unknown