Thyroglobulin-like antigens in a goiter with impaired thyroglobulin biosynthesis

A human congenital goiter has been shown to contain minute amounts of TG-like immunoreactive material (1). The subcellular distribution of the TG-like antigens after differential centrifugation of the homogenate and digitonin solubilization of the particulate fractions has been studied by means of a RIA of TG: 61% of the antigens were found in the soluble fraction, and 21% and 16% in the nuclear and microsomal ones, respectively. The analysis of each fraction by linear sucrose density gradient ultracentrifugation revealed that the antigen was heterogeneous; the main component in the soluble and nuclear fractions was a 12S protein. A 6–7S component and small amounts of 19S were found in the microsomal fraction