Binding of 125I-labelled thyrotrophin to transfected human thyrocytes (SGHTL-34 cells)

Abstract

ABSTRACT The binding of 125I-labelled bovine TSH to a human thyroid cell line (SGHTL-34) has been studied. Binding to hormonally responsive cells was time dependent, specific and reversible. Scatchard analysis of the binding data indicated the presence of a single binding site with high affinity (intrinsic dissociation constant (Kd) = 0·25 ±0·08 nmol/l; mean ± s.e.m.; n = 4) and low capacity (maximum binding (Bmax) = 104±29 fmol/mg protein; mean ± s.e.m.; n = 4). Hill plots confirmed the presence of a single site. Kinetic data demonstrated close agreement between the Kd and Bmax obtained from the competition data (Kd = 0·23±0·35 nmol/l; Bmax = 161 ±83 fmol/mg protein; n = 6). Journal of Endocrinology (1990) 127, 351–356