A theoretical analysis of the distribution of thyroxine among sites on thyroid binding globulin, thyroid binding prealbumin, and serum albumin.

A mathematical analysis was made of the distribution of free and bound thyroxine among the following: one site on thyroid binding globulin, and two sets of sites on thyroid binding prealbumin and human serum albumin. Computations were carried out using reported association constants and binding capacities as input values for a recently developed computer program. Most of the thyroxine was bound by thyroid binding globulin and the high affinity sites on thyroid binding prealbumin and human serum albumin. Computations were carried out for normal and abnormal levels of thyroxine and the binding proteins.