The iodine-containing proteins of normal and abnormal human thyroid tissue

Abstract

The method of purification of thyroglobulin by fractional precipitation with ammonium sulfate was applied to saline extracts of normal and abnormal thyroid tissues from patients given I131. Characteristic patterns were observed of the distribution of I131 between the fractions obtained. The solubility (S) and - [DELTA] S/ [DELTA] C curves for the iodine-containing proteins present in saline extracts of normal and carcinomatous thyroid tissues were found to differ. A quantitative examination by paper chromatog-raphy, of the trypsin nydrolysates of the thyroglobulins isolated from normal and carcinomatous thyroid tissue of one patient indicated that the proportions of I131 present as 3-iodotyrosine and 3:5-diiodotyro-sine were approximately 1:1 and 5:1 respectively in the normal and abnormal thyroglobulin.